Provided by: remind_05.00.02-1_amd64 bug

NAME

       remind - a sophisticated reminder service

SYNOPSIS

       remind [options] filename [date] [*rep] [time]

DESCRIPTION

       Remind reads the supplied filename and executes the commands found in it.  The commands are used to issue
       reminders  and  alarms.   Each  reminder  or alarm can consist of a message sent to standard output, or a
       program to be executed.

       If filename is specified as a single dash '-', then Remind takes its input from standard input.

       If filename happens to be a directory rather than a plain file, then Remind reads all  of  the  files  in
       that  directory  that  match the pattern "*.rem".  The files are read in sorted order; the sort order may
       depend on your locale, but should match the sort order used by the shell to expand "*.rem".

       Remind reads its files starting from the beginning to the end, or until it encounters a line  whose  sole
       content is "__EOF__" (without the quotes.)  Anything after the __EOF__ marker is completely ignored.

OPTIONS

       Remind  has a slew of options.  If you're new to the program, ignore them for now and skip to the section
       "REMINDER FILES".

       -n     The -n option causes Remind to print the next occurrence of each reminder  in  a  simple  calendar
              format.   You can sort this by date by piping the output through sort(1).  Note that the -n option
              causes any -g option to be ignored and also implicitly enables the -o option.

       -j[n]  Runs Remind in "purge" mode to get rid of expired reminders.   See  the  section  PURGE  MODE  for
              details.

       -r     The -r option disables RUN directives and the shell() function.

       -c[flags]n
              The  -c option causes Remind to produce a calendar that is sent to standard output.  If you supply
              a number n, then a calendar will be generated for n months, starting with the current  month.   By
              default, a calendar for only the current month is produced.  This option implicitly enables the -o
              option.

              You can precede n (if any) with a set of flags.  The flags are as follows:

              '+'    causes a calendar for n weeks to be produced.

              'a'    causes  Remind  to display reminders on the calendar on the day they actually occur as well
                     as on any preceding days specified by the reminder's delta.  This  also  causes  Remind  to
                     include  text  outside %"...%" sequences that would otherwise be removed (though the actual
                     %" markers themselves are removed.)

              'l'    causes Remind to use VT100 line-drawing characters to draw the  calendar.   The  characters
                     are hard-coded and will only work on terminals that emulate the VT00 line-drawing character
                     set.

              'u'    is  similar  to  'l',  but causes Remind to use UNICODE line-drawing characters to draw the
                     calendar.  The characters are hard-coded and will only work on terminals that  are  set  to
                     UTF-8  character  encoding.   This flag also enables the use of the UNICODE "left-to-right"
                     mark that can fix up formatting problems  with  right-to-left  languages  in  the  calendar
                     display.

              'c'    causes  Remind  to use VT100 escape sequences to approximate SPECIAL COLOR reminders.  Note
                     that this flag is kept  for  backwards-compatibility;  you  should  use  the  -@[n][,m][,b]
                     command-line option instead.

       -@[n][,m][,b]
              Tells  Remind  to approximate SPECIAL COLOR and SHADE reminders using VT100 escape sequences.  The
              approximation is (of necessity) very coarse, because the VT100  only  has  eight  different  color
              sequences,  each  with  one  of two brightnesses.  A color component greater than 64 is considered
              "on", and if any of the three color components is  greater  than  128,  the  color  is  considered
              "bright".

              If  you supply the optional numeric parameters, the have the following meanings:  n=0 tells Remind
              to use the standard 16 VT100 colors.  n=1 tells it to use an extended 256-color palette  supported
              by  many  terminal emulators such as xterm.  And n=2 tells it to use escape sequences that support
              true 24-bit colors, again supported by many terminal emulators such as xterm.

              If the optional m parameter is supplied following a comma, then m=0 tells Remind that the terminal
              background is dark, and Remind will brighten up dark colors to make them visible.   If  m=1,  then
              Remind  assumes  the  terminal  background  is light and it will darken bright colors to make them
              visible.  If m is specified as 2, then Remind does not perform any adjustments, and some reminders
              may be hard or impossible to see if the color is too close to the terminal background  color.   If
              you  supply  the letter t rather than a number, then Remind attempts to guess the background color
              of the terminal, even if stdout is not a terminal.

              On startup, if the standard output is a terminal, Remind attempts to  determine  if  the  terminal
              background  is  dark  or  light  by  sending a special escape sequence to determine the background
              color.  The m parameter can override this check (or force it if m is given as t.)

              If the optional b parameter is supplied following a comma, then b=0 tells Remind to ignore SPECIAL
              SHADE reminders (the default) and b=1 tells Remind to respect SPECIAL SHADE reminders by  emitting
              VT100  escape  codes  to color the background of the calendar cell.  Note that SHADE does not work
              well unless you are using the extended 256-color palette (n=1) or the true  24-bit  colors  (n=2).
              Note  that for calendar cells that are shaded, the clamping mechanism described earlier for m=0 or
              m=1 is skipped; it is assumed that if you set both the foreground color  of  a  reminder  and  the
              background color of a cell, then you know what you are doing.

       -wcol[,pad[,spc]]]
              The  -w  option  specifies the output width, padding and spacing of the formatted calendar output.
              Col specifies the number of columns in the  output  device.   If  col  is  not  specified,  or  is
              specified  as 0, it defaults to the larger of 71 or the actual width of your terminal, or to 80 if
              standard output is not a terminal.  If col is specified as the letter t, then Remind  attempts  to
              get  the width of the /dev/tty terminal device.  This is useful, for example, if you pipe calendar
              output into less; even though standard output is a  pipe,  you  want  the  calendar  to  be  sized
              correctly for your terminal window:

                      remind -c -wt .reminders | less

              Note  that  the  value  of  col  is  also  used  to  set  the system variable $FormWidth, which is
              initialized to col - 8.  See "SYSTEM VARIABLES" for details.

              Pad specifies how many lines to use to "pad" empty calendar boxes.  This defaults to  5.   If  you
              have  many  reminders  on certain days that make your calendar too large to fit on a page, you can
              try reducing pad to make the empty boxes smaller.  Spc specifies how many  blank  lines  to  leave
              between the day number and the first reminder entry.  It defaults to 1.

              Any  of col, pad or spc can be omitted, providing you provide the correct number of commas.  Don't
              use any spaces in the option.

       -s[a]n The -s option is very similar to the -c option, except that the output calendar is not  formatted.
              It  is  listed  in  a  "simple  format" that can be used as input for more sophisticated calendar-
              drawing programs.  If n starts with "+", then it is interpreted as a number of weeks.  This option
              also implicitly enables the -o option.

              If you immediately follow the s with the letter a, then Remind displays reminders on the  calendar
              on the day they actually occur as well as on any preceding days specified by the reminder's delta.

       -p[a][p][p][q]n
              The  -p  option  is  very  similar  to  the  -s option, except that the output contains additional
              information for use by the Rem2PS program, which creates a PostScript calendar, and various  other
              back-end  programs.  For this option, n cannot start with "+"; it must specify a number of months.
              The format of the -p output is described in the rem2ps(1) man page.  If you immediately follow the
              p with the letter a, then Remind displays reminders on the calendar on the day they actually occur
              as well as on any preceding days specified by the reminder's delta.  If  you  follow  the  p  with
              another  p,  then  Remind  uses  a  more  comprehensive  JSON-based format rather than the "simple
              calendar" format.  This format is also documented in the rem2ps(1) man page.  Finally, if you  use
              three p's, as in -ppp, then Remind uses a pure JSON format, again documented in rem2ps(1).  If you
              include a q letter with this option, then the normal calendar-mode substitution filter is disabled
              and the %"...%" sequences are preserved in the output.

              The -p, -pp and -ppp options implicitly enable the -o option.

              Note that the -pp or -ppp options also enable the -l option.

       -l     If  you  use  the  -l  option  in  conjunction  with the -p option, then Remind outputs additional
              information for back-end programs such as rem2ps.  This additional information lets  the  back-end
              programs correlate a reminder with the source file and line number that produced it.

       -m     The  -m  option  causes  the  -c  or -p options to produce a calendar whose first column is Monday
              rather than Sunday.  (This conforms to the international standard.)

       -v     The -v option makes the output of Remind slightly more verbose.  Currently, this causes Remind  to
              echo a bad line in case of an error, and to print a security message if a script tests the $RunOff
              system variable.

       -o     The  -o option causes Remind to ignore all ONCE directives.  Note that ONCE is also ignored if any
              of the -c, -n, -p, or -s options is used, if a repetition factor *n is used, or if  a  date  other
              than today's date is specified on the command-line.

       -t     The -t option causes Remind to trigger all non-expired reminders, regardless of the delta supplied
              for each reminder.

       -tn    If  you  supply  a  number n after the -t option, then Remind pretends that echo REM command has a
              delta of ++n, regardless of any existing delta.

       -tz    If you supply the letter z after the -t option, then Remind sets all  REM  statements'  deltas  to
              zero,  regardless of the value supplied in the REM statement itself.  In effect, this disables all
              deltas of the form +n and ++n.

       -tt[n] The -tt option causes Remind to assume a default delta of n minutes for all timed  reminders.   If
              -tt is given with no n, a default delta of 5 minutes is used.

       -h     The  -h option ("hush...") suppresses certain warning and information messages.  In particular, if
              no reminders are triggered, this mode produces no output.

       -a     The -a option causes Remind not to immediately trigger timed reminders that trigger on the current
              day.  It also causes Remind not to place timed reminders in a calendar.  If you supply two or more
              -a options, then Remind will trigger timed reminders that are in the future, but will not  trigger
              timed reminders whose time has passed.  (Regardless of how many -a options you supply, Remind will
              not include timed reminders in the calendar if at least one -a option is used.)

       -q     The -q option causes Remind not to queue timed reminders for later execution.

       -f     The  -f  option causes Remind to remain in the foreground when processing queued reminders, rather
              than forking off a background process to handle them.

       -e     The -e option diverts error messages (normally sent to the standard error stream) to the  standard
              output stream.

       -dchars
              The -d option enables certain debugging modes.  The chars specify which modes to enable:

         e      Echo all input lines

         x      Trace all expression evaluation

         t      Display all trigger date computation

         v      Dump the variable table after execution of the reminder script

         l      Echo lines when displaying error messages

         f      Trace the reading of reminder files

         s      Trace  expression parsing and display the internal expression node tree.  This is unlikely to be
                useful unless you are working on Remind's expression evaluation engine.

       -g[a|d[a|d[a|d[a|d]]]]
              Normally, reminders are issued in the order in which they are encountered in the reminder  script.
              The -g option cause Remind to sort reminders by date and time prior to issuing them.  The optional
              a  and  d  characters  specify  the  sort  order  (ascending or descending) for the date, time and
              priority fields.  See the section "SORTING REMINDERS" for more information.

              Note that -g is ignored if you use the -n option.

       -b[n]  Set the time format for the calendar and simple-calendar outputs.  N can range from 0 to  2,  with
              the  default  0.   A  value  of 0 causes times to be inserted in 12-hour (am/pm) format.  1 causes
              times to be inserted in 24-hour format, and 2 inhibits the automatic insertion  of  times  in  the
              calendar output.

       -x[n]  Sets the iteration limit for the SATISFY clause of a REM command.  Defaults to 1000.

       -kcmd  Instead  of simply printing MSG-type reminders, this causes them to be passed to the specific cmd.
              You must use '%s' where you want the body to appear, and  may  need  to  enclose  this  option  in
              quotes.   Note that all shell characters in the body of the reminder are escaped with a backslash,
              and the entire body of the reminder is passed  as  a  single  argument.   Note  that  this  option
              overrides the -r option and the RUN OFF command.

              As  an  example,  suppose  you  have an X Window program called xmessage that pops up a window and
              displays its invocation arguments.  You could use:

                        remind '-kxmessage %s &' ...

              to have all of your MSG-type reminders processed using xmessage.

              A word of warning: It is very easy to spawn dozens of xmessage processes with the above technique.
              So be very careful.  Because all shell and whitespace characters  are  escaped,  the  program  you
              execute with the -k option must be prepared to handle the entire message as a single argument.

              If  you  follow  the  -k  option  with  a  colon, then the command is applied only to queued timed
              reminders.  Normal reminders are handled as usual.  In the  above  example,  if  you  want  normal
              reminders  to  simply  be  displayed as usual, but queued reminders to be sent to notify-send, you
              could use:

                        remind '-k:notify-send %s &' ...

              You use both -kcmd1 and -k:cmd2 to use different commands for queued versus non-queued reminders.

       -z[n] Runs Remind in "daemon mode".  If n
              is supplied, it specifies how often (in minutes) Remind should wake up to check  if  the  reminder
              script  has  been changed.  N defaults to 1, and can range from 1 to 60.  Note that the use of the
              -z option also enables the -f option.

              If Remind is compiled on a system that supports inotify(7), then if the reminder  script  supplied
              on  the  command-line is actually a directory, Remind additionally checks if all files within that
              directory have been modified since startup.

              If you supply the option -zj, Remind  runs  in  a  special  mode  called  server  mode.   This  is
              documented  in  the  tkremind  man  page; see tkremind(1).  The older server mode option -z0 still
              works, but is deprecated; it uses an ad-hoc method to communicate  with  the  client  rather  than
              using JSON to communicate with the client.

       -uname Runs  Remind  with  the uid and gid of the user specified by name.  The option changes the uid and
              gid as described, and sets the environment variables HOME, SHELL and USER to the  home  directory,
              shell,  and  user name, respectively, of the specified user.  LOGNAME is also set to the specified
              user name.  This option is meant for use in shell scripts that mail reminders to all users.   Note
              that  as  of  Remind  3.00.17,  using -u implies -r -- the RUN directive and shell() functions are
              disabled.  However, if you prefix name with a +-sign, then RUN and shell() are not disabled.  That
              is, -uwhatever switches the user to whatever and disables RUN, whereas  -u+whatever  switches  the
              user to whatever but leaves RUN enabled.

              Non-root users can also use the -u option.  However, in this case, it only changes the environment
              variables as described above.  It does not change the effective uid or gid.

       -+username
              Causes  Remind  to  trust files owned by the user username.  Normally, if Remind reads a file that
              you do not own, it disables RUN and the shell() function.  This option causes  it  to  also  trust
              files  owned  by  username.   You  can supply multiple -+ options to trust multiple users, up to a
              limit of 20 trusted users.

       -y     Causes Remind to synthesize a tag for any reminder that lacks a TAG clause.

       -ivar=expr
              Sets the value of the specified var to expr, and preserves var.  Expr  can  be  any  valid  Remind
              expression.   See  the  section "INITIALIZING VARIABLES ON THE COMMAND LINE" for more details.  If
              you omit the =expr part, then var is initialized to 0.  In other words, -ivar is exactly the  same
              as -ivar=0.

       -ifunc(args)=definition
              Allows you to define a function on the command line.

       If  you supply a date on the command line, it must consist of day month year, where day is the day of the
       month, month is at least the first three letters of the English name of the month, and  year  is  a  year
       (all 4 digits) from 1990 to about 2075.  You can leave out the day, which then defaults to 1.

       If  you do supply a date on the command line, then Remind uses it, rather than the actual system date, as
       its notion of "today."  This lets you create calendars for  future  months,  or  test  to  see  how  your
       reminders  will  be  triggered in the future.  Similarly, you can supply a time to set Remind's notion of
       "now" to a particular time.  Supplying a time on the command line also implicitly enables the  -q  option
       and  disables  the  -z option.  The time may be specified in 24-hour format (eg, 13:20) or common "AM/PM"
       format (1:20pm).

       If you would rather specify the date more succinctly, you can supply it as YYYY-MM-DD or YYYY/MM/DD.  You
       can even supply a date and time on the command line as one argument: YYYY-MM-DD@HH:MM.

       In addition, you can supply a repeat parameter, which has the form *rep.  This causes Remind  to  be  run
       rep times, with the date incrementing on each iteration.  You may have to enclose the parameter in quotes
       to  avoid  shell  expansion.   See the subsection "Repeated Execution" in the section "CALENDAR MODE" for
       more information.

LONG OPTIONS

       Remind supports the following long options, which are case-sensitive:

       --version The --version option causes Remind to print its version number  to  standard  output  and  then
       exit.

       --max-execution-time=n
              Limit  the  total  execution time (as measured by the wall clock) to n seconds.  This is useful if
              Remind is invoked on potentially-untrustworthy files that could attempt to use a lot of resources.
              Note that the limit n is approximate and Remind might execute for one or two more  seconds  before
              it  is killed.  If n is specified as zero, then no limit is applied, just as if the option had not
              been used at all.

       If a limit is applied, it applies only to the foreground run of Remind.  If  Remind  finishes  processing
       the script and then starts handling queued reminders, the time limit is reset to no limit.

REMINDER FILES

       Remind uses scripts to control its operation.  You can use any text editor capable of creating plain-text
       files  to create a Remind script.  The commands inside a script can range from the very simple and almost
       immediately understandable:

               REM Mar 31 MSG International Transgender Day of Visibility

       to the baroque and obscure:

               REM [date(thisyear, 1, 1) + 180] ++5 OMIT \
               sat sun BEFORE MSG [ord(thisyear-1980)] payment due %b!

       A reminder file consists of commands, with one command per line.  Several lines can  be  continued  using
       the  backslash  character,  as  in  the  above  example.  In this case, all of the concatenated lines are
       treated as a single line by Remind.  Note that if an error occurs, Remind reports the line number of  the
       last line of a continued line.

       Remind  ignores  blank  lines,  and  lines  beginning  with  the  '#' or ';' characters.  You can use the
       semicolon as a comment character if you wish to pass a Remind script through the C  pre-processor,  which
       interprets the '#' character as the start of a pre-processing directive.

       Note that Remind processes line continuations before anything else.  For example:

            # This is a comment \
            This line is part of the comment because of line continuation \
            and so on.
            REM MSG This line is not ignored (no \ above)

       Remind  is  not  case  sensitive; you can generally use any mixture of upper- or lower-case for commands,
       parameters, invocation options, etc.

THE REM COMMAND

       The most powerful command in a Remind script is the REM command.  This command is responsible for issuing
       reminders.  Its syntax is:

              REM [ONCE] [date_spec] [back] [delta] [repeat] [PRIORITY prio]  [SKIP  |  BEFORE  |  AFTER]  [OMIT
              omit_list]  [ADDOMIT]  [NOQUEUE]  [OMITFUNC  omit_function]  [AT  time  [tdelta] [trepeat]] [SCHED
              sched_function] [WARN warn_function] [UNTIL expiry_date | THROUGH last_date] [SCANFROM scan_date |
              FROM start_date] [DURATION duration] [TAG tag] <MSG | MSF | RUN | CAL | SATISFY | SPECIAL  special
              | PS | PSFILE> body

       The  parts  of  the REM command can be specified in any order, except that the body must come immediately
       after the MSG, RUN, CAL, PS, PSFILE or SATISFY keyword.

       The REM token is optional, providing that the remainder of the command cannot  be  mistaken  for  another
       Remind  command  such  as  OMIT  or  RUN.  The portion of the REM command before the MSG, MSF RUN, CAL or
       SATISFY clause is called a trigger.

       MSG, MSF, RUN, CAL, SPECIAL, PS and PSFILE

       These keywords denote the type of the reminder.  (SATISFY is  more  complicated  and  will  be  explained
       later.)   A  MSG-type  reminder  normally prints a message to the standard output, after passing the body
       through a special substitution filter, described in the section "THE SUBSTITUTION FILTER."   However,  if
       you  have used the -k command-line option, then MSG-type reminders are passed to the appropriate program.
       Note that the options -c, -s, -p and -n disable the -k option.

       Note that you can omit the reminder type, in which case it defaults to MSG.  So you can write:

            6 January Dianne's Birthday

       although this is not recommended.

       The MSF keyword is almost the same as the MSG keyword, except that the reminder is formatted to fit  into
       a  paragraph-like format.  Three system variables control the formatting of MSF-type reminders - they are
       $FirstIndent, $SubsIndent and $FormWidth.  They are discussed in the section "SYSTEM VARIABLES."  The MSF
       keyword causes the spacing of your reminder to be altered - extra spaces are discarded,  and  two  spaces
       are  placed  after  periods  and  other  characters,  as  specified  by the system variables $EndSent and
       $EndSentIg.  Note that if the body of the reminder includes newline characters (placed there with the  %_
       sequence),  then  the  newlines  are  treated  as  the beginnings of new paragraphs, and the $FirstIndent
       indentation is used for the next line.  You can use two consecutive newlines to  have  spaced  paragraphs
       emitted from a single reminder body.

       A RUN-type reminder also passes the body through the substitution filter, but then executes the result as
       a system command.  A CAL-type reminder is used only to place entries in the calendar produced when Remind
       is run with the -c, -s or -p options.

       A  PS  or  PSFILE-type  reminder  is  used to pass PostScript code directly to the printer when producing
       PostScript calendars.  This can be used to shade certain calendar entries (see the  psshade()  function),
       include graphics in the calendar, or almost any other purpose you can think of.  You should not use these
       types  of  reminders  unless  you  are  an expert PostScript programmer.  The PS and PSFILE reminders are
       ignored unless Remind is run with the -p option.  See  the  section  "More  about  PostScript"  for  more
       details.

       A  SPECIAL-type  reminder  is  used to pass "out-of-band" information from Remind to a calendar-producing
       back-end.  It should be followed by a word indicating the type of special data being passed.  The type of
       a special reminder depends on the back-end.  For the Rem2PS back-end, SPECIAL PostScript is equivalent to
       a PS-type reminder, and SPECIAL PSFile is equivalent to a PSFILE-type reminder.  The body  of  a  SPECIAL
       reminder  is  obviously  dependent  upon the back-end.  A back-end must ignore a SPECIAL that it does not
       recognize.

       DATE SPECIFICATIONS

       A date_spec consists of zero to four parts.  These parts are day (day of month), month (month name), year
       and weekday.  Month and weekday are the English names of months and weekdays.  At least the  first  three
       characters must be used.  The following are examples of the various parts of a date_spec:

       day:   1, 22, 31, 14, 3

       month: JANUARY, feb, March, ApR, may, Aug

       year:  1990, 1993, 2030.  The year can range from 1990 to 2075.

       weekday:
              Monday, tue, Wed, THU, Friday, saturday, sundAy

       Note that there can be several weekday components separated by spaces in a date_spec.

       INTERPRETATION OF DATE SPECIFICATIONS

       The following examples show how date specifications are interpreted.

       1. Null date specification - the reminder is triggered every day.  The trigger date for a specific run is
       simply the current system date.  For example:

               REM MSG This is triggered every time Remind runs

       2. Only day present.  The reminder is triggered on the specified day of each month.  The trigger date for
       a particular run is the closest such day to the current system date.  For example:

            REM 1 MSG First of every month.
            REM 31 MSG 31st of every month that has 31 days.

       3. Only month present.  The reminder is triggered every day of the specified month.  Example:

            REM Feb MSG Every day in February

       4.  day and month present.  Examples:

            REM 6 Jan MSG Every 6th of January
            REM Feb 29 MSG Every 29th of February

       5.  Only year present. Example:

            REM 1991 MSG Every day in 1991

       6.  year and day present.  Examples:

            REM 1 1990 MSG 1st of every month in 1990
            REM 1992 23 MSG 23rd of every month in 1992

       7.  year and month present.  Examples:

            REM Feb 1991 MSG Every day in Feb 1991
            REM 1992 September MSG Every day in Sept 1992

       8.  year, month and day present.  Examples:

            REM 8 Jan 1991 MSG 8th January 1991.
            REM 1992 March 9 MSG 9th March 1992.

       9.  weekday only.  Examples:

            REM Sat MSG Every Saturday
            REM Mon Tue Wed Thu Fri MSG Every working day
            REM Monday Wednesday MSG Every Monday and Wednesday

       10.  weekday and day present.  Examples:

            REM Sat 1 MSG First Saturday of every month
            REM Mon Tue Wed Thu Fri 15 \
                 MSG 1st working day on or after 15th of every month

       11.  weekday and month present.  Examples:

            REM Mon March MSG Every Monday in March
            REM Mon Tue Wed Thu Fri Feb MSG Every working day in February

       12.  weekday, month and day present.  Examples:

            REM Mon 1 March MSG First Monday in March
            REM Sat Sun 15 July MSG First Sat or Sun on or after 15 July

       13.  weekday and year present.  Example:

            REM Sat Sun 1991 MSG Every Saturday and Sunday in 1991

       14.  weekday, day and year present.  Examples:

            REM Mon 15 1990 MSG 1st Mon after 15th of every month in 1990
            REM Mon Tue Wed Thu Fri 1 1990 \
                 MSG 1st working day of every month in 1990

       15.  weekday, month and year present.  Example:

            REM Mon Wed 1991 Feb MSG Every Mon and Wed in Feb 1991.

       16.  weekday, day, month and year present.  Example:

            REM Mon Tue Wed Thu Fri 28 Oct 1990 \
                 MSG 1st working day on or after 28 October 1990.

       Note  that  when  both  weekday  and  day  are  specified,  Remind chooses the first date on or after the
       specified day that also satisfies the weekday constraint.  It does this by picking the first date  on  or
       after the specified day that is listed in the list of weekdays.  Thus, a reminder like:

            REM Mon Tue 28 Oct 1990 MSG Hi

       would  be  issued only on Monday, 29 October, 1990.  It would not be issued on Tuesday, 30 October, 1990,
       since the 29th is the first date to satisfy the weekday constraints.

       SHORT-HAND DATE SPECIFICATIONS

       In addition to spelling out the day, month and year separately, you can specify YYYY-MM-DD or YYYY/MM/DD.
       For example, the following statements are equivalent:

            REM 5 June 2010 MSG Cool!
            REM 2010-06-05  MSG Cool!

       You can also specify a date and time as YYYY-MM-DD@HH:MM.  These statements are equivalent:

            REM 19 Dec 2010 AT 16:45 MSG Hi
            REM 2010-12-19@16:45 MSG Hi

       There's one subtlety with short-hand date specifications:  The following statements are not equivalent:

            REM 19 Dec 2010 AT 16:45 +60 MSG Hi
            REM 2010-12-19@16:45 +60 MSG Hi

       In the second statement, the "+60" is a delta that applies to the date rather than a tdelta that  applies
       to the time.  We recommend explicitly using the AT keyword with timed reminders.

       THE REMIND ALGORITHM

       Remind  uses  the  following  algorithm  to  compute  a  trigger date: Starting from the current date, it
       examines each day, one at a time, until it finds a date that satisfies the date specification, or  proves
       to  itself  that  no such date exists.  (Actually, Remind merely behaves as if it used this algorithm; it
       would be much too slow in practice.  Internally, Remind  uses  much  faster  techniques  to  calculate  a
       trigger date.)  See DETAILS ABOUT TRIGGER COMPUTATION for more information.

       BACKWARD SCANNING

       Sometimes,  it  is  necessary  to  specify a date as being a set amount of time before another date.  For
       example, the last Monday in a given month is computed as the first Monday in  the  next  month,  minus  7
       days.  The back specification in the reminder is used in this case:

            REM Mon 1 -7 MSG Last Monday of every month.

       A  back  is  specified  with  one  or  two  dashes  followed  by  an integer.  This causes Remind to move
       "backwards" from what would normally be the trigger date.  The difference between  --7  and  -7  will  be
       explained when the OMIT keyword is described.

       ADVANCE WARNING

       For some reminders, it is appropriate to receive advance warning of the event.  For example, you may wish
       to  be  reminded  of  someone's  birthday  several days in advance.  The delta portion of the REM command
       achieves this.  It is specified as one or two "+" signs followed by a number n.   Again,  the  difference
       between  the  "+"  and  "++"  forms  will  be  explained under the OMIT keyword.  Remind will trigger the
       reminder on computed trigger date, as well as on each of the n days before  the  event.   Here  are  some
       examples:

            REM 6 Jan +5 MSG Remind me of birthday 5 days in advance.

       The above example would be triggered every 6th of January, as well as the 1st through 5th of January.

       PERIODIC REMINDERS

       We  have  already seen some built-in mechanisms for certain types of periodic reminders.  For example, an
       event occurring every Wednesday could be specified as:

            REM Wed MSG Event!

       However, events that do not repeat daily, weekly, monthly or yearly require another approach.  The repeat
       component of the REM command fills this need.  To use it, you must completely specify a date (year, month
       and day, and optionally weekday); this is the start date of the repetition period.  The repeat  component
       is an asterisk followed by a number specifying the repetition period in days.

       For example, suppose you get paid every second Wednesday, and your last payday was Wednesday, 28 October,
       1992.  You can use:

            REM 28 Oct 1992 *14 MSG Payday

       This  issues  the  reminder  every  14  days, starting from 28 Oct 1992.  You can use delta and back with
       repeat.  Note, however, that the back is used only to compute the starting date; thereafter, the reminder
       repeats with the specified period.  Similarly, if you specify a weekday, it is used only to calculate the
       starting date, and does not affect the repetition period.

       SCANFROM and FROM

       The SCANFROM and FROM keywords are for advanced Remind programmers only, and will  be  explained  in  the
       section "DETAILS ABOUT TRIGGER COMPUTATION" near the end of this manual.  Note that SCANFROM is available
       only in versions of Remind from 03.00.04 up.  FROM is available only from 03.01.00 and later.

       PRIORITY

       The  PRIORITY  keyword must be followed by a number from 0 to 9999.  It is used in calendar mode and when
       sorting reminders.  If two reminders have the same trigger  date  and  time,  then  they  are  sorted  by
       priority.   If  the  PRIORITY keyword is not supplied, a default priority of 5000 is used.  (This default
       can be changed by adjusting the system variable $DefaultPrio.  See the  section  "SYSTEM  VARIABLES"  for
       more information.)

       EXPIRY DATES

       Some  reminders  should be issued periodically for a certain time, but then expire.  For example, suppose
       you have a class every Friday, and that your last class is on 11 December 1992.  You can use:

            REM Fri UNTIL 11 Dec 1992 MSG Class today.

       Another example:  Suppose you have jury duty from 30 November 1992 until 4 December 1992.  The  following
       reminder will issue the message every day of your jury duty, as well as 2 days ahead of time:

            REM 1992-11-30 *1 +2 UNTIL 1992-12-04 MSG Jury duty

       Note  that  the  repeat  of *1 is necessary; without it, the reminder would be issued only on 30 November
       (and the two days preceding.)

       As a special case, you can use the THROUGH keyword instead of  *1  and  UNTIL.   The  following  two  REM
       commands are equivalent:

            REM 1992-11-30 *1 +2 UNTIL 1992-12-04 MSG Jury duty

            REM 1992-11-30 +2 THROUGH 1992-12-04 MSG Jury duty

       If  you  have an expiry date via the use of THROUGH or UNTIL, then Remind will never trigger the reminder
       after the expiry date.  For example, if you have this:

               OMIT 2021-01-08
               REM 2021-01-01 THROUGH 2021-01-08 AFTER MSG Test

       the reminder will not be triggered on 2021-01-08, and nor will it be triggered on 2021-01-09; even though
       the AFTER keyword would normally move the 8th's reminder to  the  9th,  the  expiry  date  of  2021-01-08
       overrides that.

       THE ONCE KEYWORD

       Sometimes,  it  is  necessary  to  ensure  that reminders are run only once on a given day.  For example,
       compare the following two reminders:

               REM Fri RUN do_backup
               REM Fri ONCE RUN do_backup

       The first will be run every time you invoke Remind on a Friday, whereas the second will be run  only  the
       first time you invoke Remind on a given Friday.

       If  you  run Remind from your .login script, for example, and log in several times per day, the do_backup
       program in the first reminder will be run each time you log in.  If, however, you use the ONCE keyword in
       the reminder, the Remind checks the last access date of the reminder script.  If it is the  same  as  the
       current  date,  Remind  assumes that it has already been run, and will not issue reminders containing the
       ONCE keyword.

       Note that if you view or edit your reminder script, the last access date will be updated,  and  the  ONCE
       keyword  will not operate properly.  You can fix this by setting a timestamp file for Remind to track the
       last-run date; see the documentation of $OnceFile in the SYSTEM VARIABLES section.  If you  use  standard
       input as your Remind input file, then you must use 0 ONCE keyword to work properly.

       If  you  start Remind with the -o option, then the ONCE keyword will be ignored and any $OnceFile will be
       ignored.

       LOCALLY OMITTING WEEKDAYS

       The OMIT portion of the REM command is used to "omit" certain days when counting the delta or  back.   It
       is  specified using the keyword OMIT followed by a list of weekdays.  Its action is best illustrated with
       examples:

            REM 1 +1 OMIT Sat Sun MSG Important Event

       This reminder is normally triggered on the first of every  month,  as  well  as  the  day  preceding  it.
       However,  if  the first of the month falls on a Sunday or Monday, then the reminder is triggered starting
       from the previous Friday.  This is because the delta of +1 does not count  Saturday  or  Sunday  when  it
       counts backwards from the trigger date to determine how much advance warning to give.

       Contrast this with the use of "++1" in the above command.  In this case, the reminder is triggered on the
       first of each month, as well as the day preceding it.  The omitted days are counted.

            REM 1 -1 OMIT Sat Sun MSG Last working day of month

       Again,  in  the  above example, the back of -1 normally causes the trigger date to be the last day of the
       month.  However, because of the OMIT clause, if the first of the month falls on a Sunday or  Monday,  the
       trigger  date is moved backwards past the weekend to Friday.  (If you have globally omitted holidays, the
       reminder will be moved back past them, also.  See "The OMIT command" for more details.)

       By comparison, if we had used "--1", the reminder would be triggered  on  the  last  day  of  the  month,
       regardless of the OMIT.

       If  you  locally omit weekdays but also have globally-omitted weekdays, then the list of omitted weekdays
       is the union of the two.  Consider this example:

               OMIT Sat Sun
               REM 15 OMIT Fri Sat MSG Whatever

       In the REM command, the effective list of omitted weekdays will be Friday, Saturday and Sunday.

       COMPUTED LOCAL OMITS

       The OMITFUNC phrase of the REM command allows you to supply a function that determines whether or  not  a
       date  is  omitted.   The  function  is passed a single parameter of type DATE, and must return a non-zero
       integer if the date is considered "omitted" and 0 otherwise.  Here's an example:

               FSET _third(x) (day(x) % 3) || \
                              (wkdaynum(x) == 0) || \
                              (wkdaynum(x) == 6)
               REM OMITFUNC _third AFTER MSG Working day divisible by 3

       In the example above, the reminder is triggered every Monday  to  Friday  whose  day-of-month  number  is
       divisible by three.  Here's how it works:

       o      The  OMITFUNC _third portion causes all days for which _third(x) returns non-zero to be considered
              "omitted".  This causes all days whose day-of-month number is  not  a  multiple  of  three  to  be
              omitted.  Note that _third also returns non-zero if the weekday is Sunday or Saturday.

       o      The AFTER keyword causes the reminder to be moved after a block of omitted days.

       The  combination of OMITFUNC and AFTER keyword causes the reminder to be issued on all days whose day-of-
       month number is divisible by three, but not on Saturday or Sunday.

       Note that if you use OMITFUNC, then a local OMIT is ignored as are all global OMITs.  If you want to omit
       specific weekdays, your omit function will need to test for them specifically.  If you want to take  into
       account the global OMIT context, then your omit function will need to test for that explicitly (using the
       isomitted() function.)

       Note  that  an  incorrect  OMITFUNC might cause all days to be considered omitted.  For that reason, when
       Remind searches through omitted days,  it  terminates  the  search  after  the  SATISFY  iteration  limit
       (command-line option -x.)

       ADDING TRIGGER DATES TO THE OMIT CONTEXT

       If  the  ADDOMIT  keyword appears in a REM command, then the trigger date (if one could be calculated) is
       automatically added to the list of global OMITs.

       The command:

               REM ... whatever ... ADDOMIT MSG Foo

       is identical in behaviour to the sequence:

               REM ... whatever ... SATISFY 1
               IF trigvalid()
                   OMIT [trigdate()] MSG Foo
               ENDIF

       TIMED REMINDERS

       Timed reminders are those that have an AT keyword followed by a time and  optional  tdelta  and  trepeat.
       The  time  may  be specified in 24-hour format, with 0:00 representing midnight, 12:00 representing noon,
       and 23:59 representing one minute to midnight.  Alternatively, it may  be  specified  in  common  "AM/PM"
       format;  in this case, the hour must range from 1 to 12.  12:00am represents midnight, 12:00pm represents
       noon, and 11:59pm represents one minute to midnight.  The "am" and "pm" portions are case-insensitive and
       the "m" is optional.

       You can use either a colon or a period to separate the hours from the minutes.  That is, 13:39 and  13.39
       are equivalent.

       Remind  treats  timed  reminders  specially.  If the trigger date for a timed reminder is the same as the
       current system date, the reminder is queued for later activation.  When Remind  has  finished  processing
       the  reminder  file, it puts itself in the background, and activates timed reminders when the system time
       reached the specified time.  Note that if you use the NOQUEUE modifier in  the  REM  command,  then  this
       queuing  and  background  activation  is  not  performed.   NOQUEUE  is  useful  if you want a time to be
       associated with a reminder (eg, in the calendar) but are not interested in a popup reminder happening  at
       the specified time.

       If the trigger date is not the same as the system date, the reminder is not queued.

       For  example,  the  following  reminder,  triggered every working day, will emit a message telling you to
       leave at 5:00pm:

            REM Mon Tue Wed Thu Fri AT 17:00 MSG Time to leave!

       The following reminder will be triggered on Thursdays and Fridays, but will only be queued on Fridays:

            REM Fri ++1 AT 1:00PM MSG Lunch at 1pm Friday.

       The tdelta and trepeat have the same form as a repeat and delta,  but  are  specified  in  minutes.   For
       example, this reminder will be triggered at 12:00pm as well as 45 minutes before:

            REM AT 12:00 +45 MSG Example

       The following will be issued starting at 10:45, every half hour until 11:45, and again at noon.

            REM AT 12:00 +75 *30 MSG Example2

       The  "+75"  means  that the reminder is issued starting 75 minutes before noon; in other words, at 10:45.
       The *30 specifies that the reminder is subsequently to  be  issued  every  30  minutes.   Note  that  the
       reminder is always issued at the specified time, even if the tdelta is not a multiple of the trepeat.  So
       the  above  example  is  issued  at  10:45am,  11:15am,  11:45am,  and  12:00pm.   Note  that in the time
       specification, there is no distinction between the "+" and "++" forms of tdelta.

       Normally, Remind will issue timed reminders as it processes the reminder script, as well as queuing  them
       for  later.   If  you  do  not want Remind to issue the reminders when processing the script, but only to
       queue them for later, use the -a command-line option.  If you do not want  reminders  to  be  queued  for
       later, use the -q command-line option.

       Normally,  Remind forks a background process to handle queued reminders.  If you want Remind to remain in
       the foreground, use the -f command-line option.  This is useful, for example, in .xinitrc scripts,  where
       you can use the command:

            remind -fa myreminders &

       This ensures that when you exit X-Windows, the Remind process is killed.

       WARNING ABOUT TIMED REMINDERS

       Note:  If you use user-defined functions or variables (described later) in the bodies of timed reminders,
       then  when  the timed reminders are activated, the variables and functions have the definitions that were
       in effect at the end of the reminder script.  These definitions may not necessarily be those that were in
       effect at the time the reminder was queued.  In addition, the OMIT context is whatever was in  effect  at
       the  end  of the reminder script, which may not necessarily be the same as when the REM command was first
       processed.

       THE SCHED AND WARN KEYWORDS

       The SCHED keyword allows more precise control over the  triggering  of  timed  reminders,  and  the  WARN
       keyword  allows  precise  control  over  the  advance  triggering  of  all  types of reminders.  However,
       discussion must be deferred until after expressions and user-defined functions are  explained.   See  the
       subsection "PRECISE SCHEDULING" further on.

       TAG AND DURATION

       The  TAG keyword lets you "tag" certain reminders.  This facility is used by certain back-ends or systems
       built around Remind, such as TkRemind.  These  back-ends  have  specific  rules  about  tags;  see  their
       documentation for details.

       The TAG keyword is followed by a tag consisting of up to 48 characters.  You can have as many TAG clauses
       as you like in a given REM statement.  A tag can contain any character except for whitespace and a comma.

       If you supply the -y option to Remind, then any reminder that lacks a TAG will have one synthesized.  The
       synthesized  tag  consists  of the characters "__syn__" followed by the hexadecimal representation of the
       MD5 sum of the REM command line.  This lets you give a more-or-less unique identifier  to  each  distinct
       REM command.

       The  DURATION  keyword  makes sense only for timed reminders; it specifies the duration of an event.  For
       example, if you have a 90-minute meeting starting at 1:00pm, you could use any of the following:

            REM 5 March 2021 AT 13:00 DURATION 1:30 MSG Meeting
            REM 5 March 2021 AT 13:00 DURATION 90 MSG Meeting
            REM 5 March 2021 AT 1:00pm DURATION 1:30 MSG Meeting
            REM 5 March 2021 AT 1:00pm DURATION 90 MSG Meeting

       For long-duration reminders, it is convenient to use expressions to simplify writing the  DURATION.   For
       example, if you are away from 20 Feb 2023 through 23 Feb 2023 (a total of 4 days) you could write:

               REM 20 Feb AT 00:00 DURATION [4*24]:00 MSG away
               REM 20 Feb AT 00:00 DURATION [4*24*60] MSG away

       Note that duration is specified either as hours:minutes or just as minutes specified as an integer.

       If  you  specify  a duration of 00:00 or 0, then Remind behaves exactly as if no DURATION at all had been
       present.  Although durations specified as hours:minutes look superficially like a time-of-day,  they  are
       not; the hours component is not limited to the range 00-23.

SYNTACTIC SUGAR FOR REM

       The  REM  command  has  syntactic  sugar  to  let  you  express common reminders.  The following pairs of
       reminders are equivalent:

           REM First Monday April MSG Foo
           REM Mon 1 April        MSG Foo

           REM Second Monday May  MSG Bar
           REM Mon 8 May          MSG Bar

           REM Third Monday MSG Third Monday of every month
           REM Mon 15 MSG Third Monday of every month

           REM Fourth Sunday June 2025 MSG Fourth Sunday in June 2025
           REM Sun 22 June 2025 MSG Fourth Sunday in June 2025

           REM Last Monday MSG Last Monday of every month
           REM Mon 1 --7 MSG Last Monday of every month

           REM Last Monday April MSG Last Monday of every April
           REM Mon 1 May --7 MSG  Last Monday of every April

           REM Last Monday December 2025 MSG Last Monday of Dec 2025
           REM Monday 1 Jan 2026 --7 MSG Last Monday of Dec 2025

       Note that Last effectively adjusts the month and year, if necessary, to make the reminder trigger on  the
       correct date.

       The keyword IN is completely ignored, so you can write (for example):

           REM Second Monday in May MSG foo
           REM Last Monday in December 2025 MSG Bar

       An  alternate  form  of  back  makes  writing  reminders  easier.   The following groups of reminders are
       equivalent:

           REM ~~1 MSG Last day of every month
           REM Lastday MSG  Last day of every month
           REM 1 --1 MSG Last day of every month

           REM May ~~1 MSG Last day of May
           REM Lastday May MSG Last day of May
           REM 1 June --1 MSG Last day of May

           REM Dec 2025 ~~1 MSG Last day of December 2025
           REM Lastday Dec 2025 MSG Last day of December 2025
           REM 1 Jan 2026 --1 MSG Last day of December 2025

           REM Apr ~1 OMIT SAT SUN MSG Last workday of April
           REM Lastworkday April OMIT SAT SUN MSG Last workday of April
           REM 1 May -1 OMIT SAT SUN MSG Last workday of April

           REM Apr ~~7 MSG Seventh-last day of April
           REM 1 May --7 MSG Seventh-last day of April

           REM Apr ~2 OMIT SAT SUN MSG Second-last workday of April
           REM 1 May -2 OMIT SAT SUN MSG Second-last workday of April

       As we see, "Lastday" is equivalent to ~~1 and "Lastworkday" to ~1.

       Note that the First/Second/Third/Fourth/Last keywords and the ~ and ~~ form of back imply a value for the
       day   of   the   month;   as   such,   they   cannot   be   combined   with   a    day.     Additionally,
       First/Second/Third/Fourth/Last must have at least one weekday name.  The following are illegal:

           REM First Monday 3 June MSG Huh?
           REM April 3 ~~1 MSG What?
           REM Second June MSG Where's the weekday???

THE SUBSTITUTION FILTER

       Before  being  processed,  the body of a REM command is passed through a substitution filter.  The filter
       scans for  sequences  "%x"  (where  "x"  is  any  letter  and  certain  other  characters)  and  performs
       substitutions as shown below.  (All dates refer to the trigger date of the reminder.)

       %a     is replaced with "on weekday, day month, year"
              For example, consider the reminder:

              REM 18 Oct 1990 +4 MSG Meeting with Bob %a.

              On 16 October 1990, it would print "Meeting with Bob on Thursday, 18 October, 1990."

              On 17 October 1990, it would print "Meeting with Bob tomorrow."

              On 18 October 1990, it would print "Meeting with Bob today."

       %b     is  replaced with "in diff day's time" where diff is the actual number of days between the current
              date and the trigger date.  (OMITs have no effect.)
              For example, consider:

              REM 18 Oct 1990 +4 MSG Meeting with Bob %b.

              On 16 October 1990, it would print "Meeting with Bob in 2 days' time."

              On 17 October 1990, it would print "Meeting with Bob tomorrow."

              On 18 October 1990, it would print "Meeting with Bob today."

       %c     is replaced with "on weekday"
              Example: REM 18 Oct 1990 +4 MSG Meeting with Bob %c.

              On 16 October 1990, it would print "Meeting with Bob on Thursday."

              On 17 October 1990, it would print "Meeting with Bob tomorrow."

              On 18 October 1990, it would print "Meeting with Bob today."

       %d     is replaced with "day", the day of the month.

       %e     is replaced with "on dd-mm-yyyy"

       %f     is replaced with "on mm-dd-yyyy"

       %g     is replaced with "on weekday, day month"

       %h     is replaced with "on dd-mm"

       %i     is replaced with "on mm-dd"

       %j     is replaced with "on weekday, month day-th, year"  This form appends the  characters  "st",  "nd",
              "rd" or "th" to the day of the month, as appropriate.

       %k     is replaced with "on weekday, month day-th"

       %l     is replaced with "on yyyy-mm-dd"

       %m     is replaced with "month", the name of the month.

       %n     is replaced with the number (1 to 12) of the month.

       %o     is  replaced  with " (today)" if and only if the current system date is the same as the date being
              used by Remind as the current date.  Recall that you can specify a date for Remind to use  on  the
              command  line.   This  substitution  is  not generally useful in a REM command, but is useful in a
              BANNER command.  (See "The BANNER Command.")

       %p     is replaced with "s" if the diff between the current date and the trigger date is not 1.  You  can
              use this to construct reminders like:
              REM 1 Jan +4 MSG %x day%p to go before New Year!

       %q     is  replaced with "'s" if the diff between the trigger date and the current date is 1.  Otherwise,
              it is replaced with "s'"  This can be used as follows:
              REM 1 Jan +4 MSG New Year in %x day%q time!

       %r     is replaced with the day of the month (01 to 31) padded with a leading zero if needed  to  pad  to
              two digits.

       %s     is replaced with "st", "nd", "rd" or "th" depending on the day of the month.

       %t     is replaced with the number of the month (01 to 12) padded to two digits with a leading zero.

       %u     is  replaced  with "on weekday, day-th month, year"  This is similar to %a except that "st", "nd",
              "rd" or "th" is added to the day as appropriate.

       %v     is replaced with "on weekday, day-th month"

       %w     is replaced with "weekday", the name of the day of the week.

       %x     is replaced with the diff between the current date and the trigger date.  The diff is  defined  as
              the  actual  number  of  days  between  these  two  dates;  OMITs  are  not counted.  (Strict date
              subtraction is performed.)

       %y     is replaced with "year", the year of the trigger date.

       %z     is replaced with "yy", the last two digits of the year.

       %_     (percent-underscore) is replaced  with  a  newline.   You  can  use  this  to  achieve  multi-line
              reminders.

       %1     is  replaced with "now", "m minutes from now", "m minutes ago", "h hours from now", "h hours ago",
              "h hours and m minutes from now" or "h hours and m  minutes  ago",  as  appropriate  for  a  timed
              reminder.   Note  that  unless  you  specify the -a option, timed reminders will be triggered like
              normal reminders, and thus a timed reminder that occurred earlier in the  day  may  be  triggered.
              This causes the need for the "...ago" forms.

       %2     is replaced with "at hh:mmam" or "..pm" depending on the AT time of the reminder.

       %3     is replaced with "at hh:mm" in 24-hour format.

       %4     is  replaced  with  "mm" where mm is the number of minutes between "now" and the time specified by
              AT.  If the AT time is earlier than the current time, then the result is negative.

       %5     is replaced with "ma" where ma is the absolute value of the number produced by %4.

       %6     is replaced with "ago" or "from now", depending on the relationship between the AT  time  and  the
              current time.

       %7     is  replaced with the number of hours between the AT time and the current time.  It is always non-
              negative.

       %8     is replaced with the number of minutes between the AT time and the current time, after  the  hours
              (%7) have been subtracted out.  This is a number ranging from 0 to 59.

       %9     is replaced with "s" if the value produced by %8 is not 1.

       %0     is replaced with "s" if the value produced by %7 is not 1.

       %!     is replaced with "is" if the current time is before the AT time, or "was" if it is after.

       %@     is similar to %2 but displays the current time.

       %#     is similar to %3 but displays the current time.

       %"     (percent-doublequote  -  ") is removed.  This sequence is not used by the substitution filter, but
              is used to tell Remind which text to include in a calendar entry when the -c, -s or -p  option  is
              chosen.  See "CALENDAR MODE"

       Notes:

       o      Remind normally prints a blank line after each reminder; if the last character of the body is "%",
              the  blank  line  will not be printed.  You can globally suppress the extra blank lines by setting
              $AddBlankLines to 0.

       o      Substitutions a, b, c, e, f, g, h, i, j, k, l, u and v  all  are  replaced  with  "today"  if  the
              current  date  equals  the  trigger  date,  or "tomorrow" if the trigger date is one day after the
              current date.  Thus, they are not the same as substitutions built up from the simpler %w, %y, etc.
              sequences.

       o      The a, c, e, f, g, h, i, j, k, l, u, v, 2, and 3 substitutions may be preceded by an asterisk (for
              example, %*c) which causes the word "at" or "on" that would normally be included in the output  to
              be omitted.

       o      Any  of  the  substitutions  dealing with time (0 through 9 and '!')  produce undefined results if
              used in a reminder that does not have an AT keyword.  Also, if a reminder has a delta and  may  be
              triggered  on several days, the time substitutions ignore the date.  Thus, the %1 substitution may
              report that a meeting is in 15 minutes, for example, even though it may only be in  2  days  time,
              because a delta has triggered the reminder.  It is recommended that you use the time substitutions
              only in timed reminders with no delta that are designed to be queued for timed activation.

       o      Capital letters can be used in the substitution sequence, in which case the first character of the
              substituted string is capitalized (if it is normally a lower-case letter.)

       o      All  other  characters  following  a "%" sign are simply copied.  In particular, to get a "%" sign
              out, use "%%" in the body.  To start the body of a reminder with a space, use "% ",  since  Remind
              normally scans for the first non-space character after a MSG, CAL or RUN token.

THE OMIT COMMAND

       In addition to being a keyword in the REM command, OMIT is a command in its own right.  Its syntax is:

              OMIT weekday [weekday...]

              or:

              OMIT [day] month [year]

              or:

              OMIT [day1] month1 [year1] THROUGH [day2] month2 [year2]

       The OMIT command is used to "globally" omit certain days (usually holidays).  These globally-omitted days
       are  skipped  by  the  "-"  and  "+"  forms  of back and delta, but not by the "--" and "++" forms.  Some
       examples:

           OMIT Saturday Sunday
           OMIT 1 Jan
           OMIT 7 Sep 1992
           OMIT 15 Jan THROUGH 14 Feb
           OMIT May     # Equivalent to OMIT May 1 THROUGH May 31
           OMIT 25 Dec THROUGH 4 Jan
           OMIT 2023-05-03 THROUGH 2023-05-12
           OMIT Jun THROUGH July  # Equivalent to OMIT Jun 1 THROUGH July 31

       The first example omits every Saturday and Sunday.  This is useful for reminders that  shouldn't  trigger
       on weekends.

       The second example specifies a holiday that occurs on the same date each year - New Year's Day.

       The  third example specifies a holiday that changes each year - Labour Day.  For these types of holidays,
       you must create an OMIT command for each year.  (Later, in the description of expressions and some of the
       more advanced features of Remind, you will see how to automate this for some cases.)

       As with the REM command, you can use shorthand specifiers for dates; the following are equivalent:

            OMIT 7 Sep 1992
            OMIT 1992-09-07

       For convenience, you can use a delta and MSG or RUN keyword in the OMIT command.  The following sequences
       are equivalent:

            OMIT 1 Jan
            REM 1 Jan +4 MSG New year's day is %b!

            and

            OMIT 1 Jan +4 MSG New year's day is %b!

       The THROUGH keyword lets you conveniently OMIT a range of days.  For example, the following sequences are
       equivalent:

            OMIT 3 Jan 2011
            OMIT 4 Jan 2011
            OMIT 5 Jan 2011

            and

            OMIT 3 Jan 2011 THROUGH 5 Jan 2011

       Note that Remind has a compiled-in limit to the number of full OMITs.  If you omit a range  of  N  fully-
       specified (ie, year included) days, then N full OMITs are used up.  Trying to omit a very large range may
       result in the error "Too many full OMITs"

       You can make a THROUGH OMIT do double-duty as a REM command as long as both dates are fully specified

            OMIT 6 Sep 2010 THROUGH 10 Sep 2010 MSG Vacation

       If  you  use  a THROUGH clause, then either the year must be supplied before and after the THROUGH, or it
       must be missing before and after the THROUGH.  The following are legal:

           OMIT 25 Dec THROUGH 6 Jan
           OMIT 25 Dec 2024 THROUGH 6 Jan 2025

       But the following are not:

           OMIT 25 Dec THROUGH 6 Jan 2025
           OMIT 25 Dec 2024 THROUGH 6 Jan

       You can debug your global OMITs with the following command:

            OMIT DUMP

       The OMIT DUMP command prints the current global omits to standard output.

       THE BEFORE, AFTER AND SKIP KEYWORDS

       Normally, days that are omitted, whether by a global OMIT command or the local OMIT or OMITFUNC  keywords
       in a REM statement, only affect the counting of the -back or the +delta.  For example, suppose you have a
       meeting every Wednesday.  Suppose, too, that you have indicated 11 Nov as a holiday:

            OMIT 11 Nov +4 MSG Remembrance Day
            REM Wed +1 MSG Code meeting %b.

       The  above  sequence  will  issue  a reminder about a meeting for 11 November 1992, which is a Wednesday.
       This is probably incorrect.  There are three options:

       BEFORE This keyword moves the reminder to before any omitted days.  Thus, in the above  example,  use  of
              BEFORE would cause the meeting reminder to be triggered on Tuesday, 10 November 1992.

       AFTER  This  keyword  moves  the  reminder  to after any omitted days.  In the above example, the meeting
              reminder would be triggered on Thursday, 12 November 1992.

       SKIP   This keyword causes the reminder to be skipped completely on any omitted days.  Thus, in the above
              example, the reminder would not be triggered on 11 November 1992.  However, it would be  triggered
              as usual on the following Wednesday, 18 November 1992.

       The  BEFORE  and AFTER keywords move the trigger date of a reminder to before or after a block of omitted
       days, respectively.  Suppose you normally run a backup on the first day of the month.   However,  if  the
       first day of the month is a weekend or holiday, you run the backup on the first working day following the
       weekend or holiday.  You could use:

            REM 1 OMIT Sat Sun AFTER RUN do_backup

       Let's  examine  how the trigger date is computed.  The 1 specifies the first day of the month.  The local
       OMIT keyword causes the AFTER keyword to move the reminder forward past  weekends.   Finally,  the  AFTER
       keyword will keep moving the reminder forward until it has passed any holidays specified with global OMIT
       commands.

THE DO AND INCLUDE COMMANDS

       Remind  allows you to include other files in your reminder script, similar to the C preprocessor #include
       directive.  For example, your system administrator  may  maintain  a  file  of  holidays  or  system-wide
       reminders.  You can include these in your reminder script as follows:

            INCLUDE /usr/share/remind/holidays
            INCLUDE /usr/share/remind/reminders

       (The actual pathnames vary from system to system - ask your system administrator.)

       INCLUDE files can be nested up to a depth of 8.

       If you specify a filename of "-" in the INCLUDE command, Remind will begin reading from standard input.

       If  you  specify  a  directory  as  the  argument  to INCLUDE, then Remind will process all files in that
       directory that match the shell pattern "*.rem".  The files are processed in sorted order; the sort  order
       matches that used by the shell when it expands "*.rem".

       Note  that  the  file  specified  by  an  INCLUDE  command is interpreted relative to the current working
       directory of the Remind process.  If you want to include a file relative to the directory containing  the
       currently-processing    file,    use    DO    instead.    For   example,   if   the   current   file   is
       /home/user/.reminders/foo.rem and Remind's working directory is /home/user, then:

           # Read /home/user/.reminders/bar.rem
           DO bar.rem

           # Read /usr/share/bar.rem - absolute path
           DO /usr/share/bar.rem

           # Read /home/user/bar.rem
           INCLUDE bar.rem

           # Read /usr/share/bar.rem - absolute path
           INCLUDE /usr/share/bar.rem

       Arguably, the INCLUDE command should have worked the way DO does right from the start,  but  changing  it
       would have broken backward-compatibility, hence the introduction of DO.

       Note  that  if the currently-processing reminders file was specified as a symbolic link to a file that is
       not in the same directory as the symbolic link itself, DO will fail.  Remind does not  resolve  the  real
       path of symbolic links, so you should avoid using symbolic links to files.

THE RUN COMMAND

       If you include other files in your reminder script, you may not always entirely trust the contents of the
       other files.  For example, they may contain RUN-type reminders that could be used to access your files or
       perform  undesired  actions.   The  RUN command can restrict this:  If you include the command RUN OFF in
       your top-level reminder script, any reminder or expression that would normally execute a  system  command
       is  disabled.   RUN ON will re-enable the execution of system commands.  Note that the RUN ON command can
       only be used in your top-level reminder script; it will not work in any files  accessed  by  the  INCLUDE
       command.  This is to protect you from someone placing a RUN ON command in an included file.  However, the
       RUN OFF command can be used at top level or in an included file.

       If  you  run  Remind with the -r command-line option, RUN-type reminders and the shell() function will be
       disabled, regardless of any RUN commands in the reminder script.  However, any command supplied with  the
       -k option will still be executed.

       In  addition,  Remind  contains a few other security features.  It will not read a file that is group- or
       world-writable.  It will not run set-uid.  If it reads a file you don't own, it will disable RUN and  the
       shell() function.  And if it is run as root, it will only read files owned by root.

       Note  that  if Remind reads standard input, it does not attempt to check the ownership of standard input,
       even if it is coming from a file, and hence does not disable RUN and shell() in this situation.

THE EXPR COMMAND

       Remind lets you completely disable expression evaluation.  This could be useful if you are running Remind
       on a somewhat-untrustworthy file that is not expected to  contain  expressions.   To  disable  expression
       evaluation, use:

               EXPR OFF

       If Remind encounters an expression while EXPR OFF is in effect, it returns an error

       To re-enable expression evaluation, use:

               EXPR ON

       As with RUN ON, EXPR ON can be used only in the top-level script, not in an included file.

THE INCLUDECMD COMMAND

       Remind  allows  you  to  execute a shell command and evaluate the output of that command as if it were an
       included file.  For example, you could have scripts that extract reminders out of a  database  and  print
       them on stdout as REM commands.  Here is an example:

            INCLUDECMD extract_reminders_for dfs

       We  assume  that the command "extract_reminders_for" extracts reminders out of a central database for the
       named user.  Another use-case of INCLUDECMD is if you have your reminders stored in a file in  some  non-
       Remind  format;  you  can  write  a  command  that  transforms  them to Remind format and then Remind can
       "include" the file with an appropriate INCLUDECMD command.

       Note that if RUN is disabled, then INCLUDECMD will fail with the error message "RUN disabled"

       INCLUDECMD passes the rest of the line to popen(3), meaning that the command is executed  by  the  shell.
       As  such, shell metacharacters may need escaping or arguments quoting, depending on what you're trying to
       do.  Remind itself does not perform any modification of the command line (apart from  the  normal  [expr]
       expression-pasting mechanism).

       If the command passed to INCLUDECMD begins with an exclamation mark "!", then Remind disables RUN for the
       output  of  the  command.   If  you  are running a command whose output you don't quite trust, you should
       prefix it with "!" so that any RUN commands it emits fail.

       An INCLUDECMD command counts towards the INCLUDE nesting depth.   For  any  given  Remind  run,  a  given
       INCLUDECMD  command  is  only  executed  once and the results are cached.  For example, if you generate a
       calendar, each unique INCLUDECMD command is run just  once,  not  once  for  each  day  of  the  produced
       calendar.   "Uniqueness"  is determined by looking at the command that will be passed to the shell, so if
       (for example) your INCLUDECMD uses expression-pasting that results in differences depending on the  value
       of today(), then each unique version of the command will be executed once.

THE BANNER COMMAND

       When Remind first issues a reminder, it prints a message like this:

            Reminders for Friday, 30th October, 1992 (today):

       (The  banner  is  not  printed  if  any of the calendar-producing options is used, or if the -k option is
       used.)

       The BANNER command lets you change the format.  It should appear before any REM commands.  The format is:

              BANNER format

       The format is similar to the body of a REM command.  It is passed through the substitution  filter,  with
       an implicit trigger of the current system date.  Thus, the default banner is equivalent to:

            BANNER Reminders for %w, %d%s %m, %y%o:

       You can disable the banner completely with BANNER %.  Or you can create a custom banner:

            BANNER Hi - here are your reminders for %y-%t-%r:

CONTROLLING THE OMIT CONTEXT

       Sometimes,  it is necessary to temporarily change the global OMITs that are in force for a few reminders.
       Three commands allow you to do this:

       PUSH-OMIT-CONTEXT
              This command saves the current global OMITs on an internal stack.

       CLEAR-OMIT-CONTEXT
              This command clears all of the global OMITs, starting you off with a "clean slate."

       POP-OMIT-CONTEXT
              This command restores the global OMITs that were saved by the most recent PUSH-OMIT-CONTEXT.

       For example, suppose you have a block of reminders that require a clear OMIT context, and that they  also
       introduce  unwanted  global OMITs that could interfere with later reminders.  You could use the following
       fragment:

            PUSH-OMIT-CONTEXT   # Save the current context
            CLEAR-OMIT-CONTEXT  # Clean the slate
            # Block of reminders goes here
            POP-OMIT-CONTEXT    # Restore the saved omit context

EXPRESSIONS

       In certain contexts, to be described later,  Remind  will  accept  expressions  for  evaluation.   Remind
       expressions resemble C expressions, but operate on different types of objects.

       DATA TYPES

       Remind expressions operate on five types of objects:

       INT    The  INT  data type consists of the integers representable in one machine word.  The INT data type
              corresponds to the C "int" type.

       STRING The STRING data type consists of strings  of  characters.   It  is  somewhat  comparable  to  a  C
              character array, but more closely resembles the string type in BASIC.

       TIME   The TIME data type is used for two different purposes:  To represent a time of day with one-minute
              precision  or  to  represent a duration with one-minute precision.  The context of where a TIME is
              used determines whether it is interpreted as a time of day or a duration.

              In contexts where a TIME represents a time of day, it may range from 00:00 to 23:59 and is  stored
              internally as an integer from 0 to 1439 representing the number of minutes since midnight.

              In  contexts  where  a  TIME  represents a duration, there is no upper limit on the hour component
              (beyond that imposed by the restriction that a duration expressed in minutes  must  fit  into  the
              signed  integer  type  of  your CPU architecture.)  Internally, a duration is stored as an integer
              number of minutes.

       DATE   The DATE data type consists of dates (later than 1 January 1990.)  Internally,  DATE  objects  are
              stored as the number of days since 1 January 1990.

       DATETIME
              The  DATETIME  data  type  consists of a date and time together.  Internally, DATETIME objects are
              stored as the number of minutes since midnight, 1 January 1990.   You  can  think  of  a  DATETIME
              object as being the combination of DATE and TIME parts.

       CONSTANTS

       The following examples illustrate constants in Remind expressions:

       INT constants
              12, 36, -10, 0, 1209

       STRING constants
              "Hello there", "This is a test", "\nHello\tThere", ""

              Note that the empty string is represented by "".  Remind supports the escape sequences "\a", "\b",
              "\f",  "\n",  "\r",  "\t"  and  "\v"  which have the same meanings as their counterparts in C.  To
              include a quote in a string, use "\"".  Any other character preceded by a  backslash  is  inserted
              into  the  string as-is, but the backslash itself is removed.  To include a backslash in a string,
              use "\\".

       TIME constants
              12:33, 0:01, 14:15, 16:42, 12.16, 13.00, 1.11, 4:30PM, 12:20am

              Note that TIME constants may be written in 24-hour format or in common "AM/PM" format.  If you use
              "AM/PM" format, then the hour can range from 1 to 12.  Either a period or colon  can  be  used  to
              separate  the  minutes  from the hours.  However, Remind will consistently output times in 24-hour
              format using only one separator character.  (The output separator character is chosen at  compile-
              time.)

              If the TIME is used where Remind expects a time-of-day (for example, in an AT clause), then it can
              be written in 24-hour format (ranging from 00:00 to 23:59) or 12-hour format (ranging from 12:00am
              to  11:59pm).   If  the TIME is used where Remind expects a duration, it must not have an am or pm
              suffix and the hour can be as large as you want, so long as the total number  of  minutes  in  the
              duration fits in a signed integer variable.

       DATE constants
              DATE  constants  are  expressed  as  'yyyy/mm/dd'  or  'yyyy-mm-dd', and the single quotes must be
              supplied.  This distinguishes date constants from division or subtraction of integers.  Examples:

              '1993/02/22', '1992-12-25', '1999/01/01'

              Note that DATE values are printed without the quotes.  Although either '-' or '/' is accepted as a
              date separator on input, when dates are printed, only one will be used.  The choice of whether  to
              use  '-'  or '/' is made at compile-time.  Note also that versions of Remind prior to 03.00.01 did
              not support date constants.  In those versions, you must create dates using the  date()  function.
              Also, versions prior to 03.00.02 did not support the '-' date separator.

       DATETIME constants
              DATETIME  constants  are  expressed  similarly  to DATE constants with the addition of an "@HH:MM"
              part, optionally followed by "am" or "pm".  For example:

              '2008-04-05@23:11', '1999/02/03@14:06', '2001-04-07@08:30', '2020-01-01@3:20pm'

              DATETIME values are printed without the quotes.  Notes about date and  time  separator  characters
              for DATE and TIME constants apply also to DATETIME constants.

       ZERO VALUES

       The non-string types all have an associated zero value, which is treated as "false" by the IF command and
       the logical operators.  The zero values are:

              INT - 0

              DATE - '1990-01-01'

              TIME - 00:00

              DATETIME - '1990-01-01@00:00'

       Additionally,  for  the  purpose of the IF command (but not the logical operators) the empty string "" is
       considered a false value.

       OPERATORS

       Remind has the following operators.  Operators on the same line have equal precedence, while operators on
       lower lines have lower precedence than those on higher lines.  The operators approximately correspond  to
       C operators.

            !  -            (unary logical negation and arithmetic negation)
            *  /  %         (multiplication, division, modulus)
            +  -            (addition/concatenation, subtraction)
            <  <=  >  >=    (comparisons)
            ==  !=          (equality and inequality tests)
            &&              (logical AND)
            ||              (logical OR)

       DESCRIPTION OF OPERATORS

       !      Logical  negation.   Can  be  applied  to  an INT type.  If the operand is non-zero, returns zero.
              Otherwise, returns 1.

       -      Unary minus.  Can be applied to an INT.  Returns the negative of the operand.

       *      Multiplication.  Returns the product of two INTs.  Alternatively, if one argument is a STRING  and
              the other an INT, returns a STRING consisting of the INT number of repeats of the original STRING.
              In this case, the INT argument cannot be negative.

       /      Integer division.  Returns the quotient of two INTs, discarding the remainder.

       %      Modulus.  Returns the remainder upon dividing one INT by another.

       +      Has several uses.  These are:

              INT + INT - returns the sum of two INTs.

              INT  +  TIME  or  TIME + INT - returns a TIME obtained by adding INT minutes to the original TIME.
              The result will always range from 00:00 through 23:59.

              TIME + TIME treats the second TIME parameter as a duration, converting it to an integer number  of
              minutes past midnight, and then performs addition as with TIME + INT.

              INT + DATE or DATE + INT - returns a DATE obtained by adding INT days to the original DATE.

              INT  +  DATETIME  or  DATETIME  +  INT  - returns a DATETIME obtained by adding INT minutes to the
              original DATETIME.

              DATETIME + TIME or TIME + DATETIME treats the TIME parameter as a duration, converting  it  to  an
              integer number of minutes past midnight, and then performs addition as with DATETIME + INT.

              STRING + STRING - returns a STRING that is the concatenation of the two original STRINGs.

              STRING  +  anything  or anything + STRING - converts the non-STRING argument to a STRING, and then
              performs concatenation.  See the coerce() function.

       -      Has several uses.  These are:

              INT - INT - returns the difference of two INTs.

              DATE - DATE - returns (as an INT) the difference in days between two DATEs.

              TIME - TIME - returns (as an INT) the difference in minutes between two TIMEs.

              DATETIME - DATETIME - returns (as an INT) the difference in minutes between two DATETIMEs.

              DATE - INT - returns a DATE that is INT days earlier than the original DATE.

              TIME - INT - returns a TIME that is INT minutes earlier than the original TIME.

              DATETIME - INT - returns a DATETIME that is INT minutes earlier than the original DATETIME.

              DATETIME - TIME - coerces the TIME to an INT and then performs subtraction as above.

       <, <=, >, and >=
              These are the comparison operators.  They can take operands of any type, but both operands must be
              of the same type.  The comparison operators return 1 if the comparison is true,  or  0  if  it  is
              false.   Note  that string comparison is done following the lexical ordering of characters on your
              system, and that upper and lower case are distinct for these operators.

       ==, != == tests for equality, returning 1 if its operands are equal, and 0 if they are not.  != tests for
              inequality.

              If the operands are not of the  same  type,  ==  returns  0  and  !=  returns  1.   Again,  string
              comparisons are case-sensitive.

       &&     This is the logical AND operator.  Neither of its operands can be STRING type.  Returns the second
              operand if both operands are non-zero.  Otherwise, returns whichever operand is zero.

       ||     This  is  the  logical  OR  operator.  Neither of its operands can be STRING type.  It returns the
              first operand that is non-zero; if both operands are zero, then returns the second operand.

       NOTES

       If the result of an addition, subtraction or multiplication operation would not fit in a  C  "int"  type,
       Remind  issues  a  "Number  too high" error.  Unlike C, integer operations will not simply give the wrong
       answer in case of overflow.

       Operators of equal precedence are always evaluated from left to right, except where  parentheses  dictate
       otherwise.   This  is  important,  because the enhanced "+" operator is not necessarily associative.  For
       example:

            1 + 2 + "string" + 3 + 4  yields "3string34"
            1 + (2 + "string") + (3 + 4)  yields "12string7"
            12:59 + 1 + "test"  yields "13:00test"
            12:59 + (1 + "test")  yields "12:591test"

       The logical operators are so-called short-circuit operators, as they are in C.  This means  that  if  the
       first  operand  of || is true, then the second operand is not evaluated.  Similarly, if the first operand
       of && is false, then the second operand is not evaluated.

       VARIABLES

       Remind allows you to assign values to variables.  The SET command is used as follows:

       SET var expr

       Var is the name of a variable.  It must start with a letter or underscore, and consist only  of  letters,
       digits and underscores.  Only the first 64 characters of a variable name are significant.  Variable names
       are not case sensitive; thus, "Afoo" and "afOo" are the same variable.  Examples:

            SET a 10 + (9*8)
            SET b "This is a test"
            SET mydir getenv("HOME")
            SET time 12:15
            SET date today()

       Note that variables themselves have no type.  They take on the type of whatever you store in them.

       Variables set with SET or on the command-line with -ivar=expr have global scope.

       To delete a variable, use the UNSET command:

       UNSET var [var...]

       For example, to delete all the variables declared above, use:

            UNSET a b mydir time date

       SYSTEM VARIABLES

       In  addition  to the regular user variables, Remind has several "system variables" that are used to query
       or control the operating state of Remind.  System variables are available starting from version  03.00.07
       of Remind.

       All system variables begin with a dollar sign '$'.  They can be used in SET commands and expressions just
       as  regular  variables  can.   All system variables always hold values of a specified type.  In addition,
       some system variables cannot be modified, and you cannot create new system variables.   System  variables
       can be initialized on the command line with the -i option, but you may need to quote them to avoid having
       the shell interpret the dollar sign.  System variable names are not case-sensitive.

       The  following  system  variables  are  defined.  Those marked "read-only" cannot be changed with the SET
       command.  All system variables hold values of type INT, unless otherwise specified.

       $AddBlankLines
              If set to 1 (the default), then Remind normally prints a blank line  after  the  banner  and  each
              reminder.   (This  can be suppressed by ending the reminder or banner with a single percent sign.)
              If $AddBlankLines is set to 0, then Remind does not print the blank line.  In this case, ending  a
              reminder  with  %  has no effect.  If you do want a blank line after a reminder, end it with %_ to
              insert a newline.

       $CalcUTC
              If 1 (the default), then Remind uses C library  functions  to  calculate  the  number  of  minutes
              between  local  and Universal Time Coordinated.  This affects astronomical calculations (sunrise()
              for example.)  If 0, then you must supply the number of minutes between local and  Universal  Time
              Coordinated in the $MinsFromUTC system variable.

       $CalMode (read-only)
              If non-zero, then the -c option was supplied on the command line.

       $Daemon (read-only)
              If  "daemon  mode" -z was invoked, contains the number of minutes between wakeups.  If not running
              in daemon mode, contains 0.  In server mode (either -z0 or -zj), contains -1.

       $DateSep
              This variable can be set only to "/" or "-".  It holds the character used to separate portions  of
              a date when Remind prints a DATE or DATETIME value.

       $DefaultColor
              This  variable  can  be  set to a string that has the form of three space-separated numbers.  Each
              number must be an integer from 0 to 255, or all three numbers must be -1.  The  default  value  of
              $DefaultColor  is "-1 -1 -1", which suppresses default coloring of MSG-type reminders.  If you set
              $DefaultColor to any other value, then all MSG-,  MSF-  and  CAL-type  reminders  are  effectively
              converted into SPECIAL COLOR reminders whose color value is specified by $DefaultColor.

              Unlike  other  system  variables,  the  value  of  $DefaultColor is not preserved between calendar
              iterations; rather, it is reset to "-1 -1 -1" at the start of each iteration.

       $DefaultPrio
              The default priority assigned to reminders without  a  PRIORITY  clause.   You  can  set  this  as
              required  to  adjust  the  priorities of blocks of reminders without having to type priorities for
              individual reminders.  At startup, $DefaultPrio is set to 5000; it can range from 0 to 9999.

       $DefaultTDelta
              The default time delta used if no +N is given in an AT clause.  This is normally 0, but can be set
              with the -tt option or explicitly set in your script.  If $DefaultDelta is non-zero, you  can  use
              an explicit delta of +0 in an AT clause to countermand the default delta.

       $DeltaOverride (read-only)
              If non-zero, corresponds to the n argument given to a -tn command-line option.

       $DontFork (read-only)
              If non-zero, then the -c option was supplied on the command line.

       $DontTrigAts (read-only)
              The number of times that the -a option was supplied on the command line.

       $DontQueue (read-only)
              If non-zero, then the -q option was supplied on the command line.

       $EndSent (STRING type)
              Contains a list of characters that end a sentence.  The MSF keyword inserts two spaces after these
              characters.  Initially, $EndSent is set to ".!?" (period, exclamation mark, and question mark.)

       $EndSentIg (STRING type)
              Contains  a list of characters that should be ignored when MSF decides whether or not to place two
              spaces after a sentence.  Initially, is set to "'>)]}"+CHAR(34) (single-quote, greater-than, right
              parenthesis, right bracket, right brace, and double-quote.)

              For example, the default values work as follows:

                   MSF He said, "Huh! (Two spaces will follow this.)"  Yup.

              because the final parenthesis and quote are ignored (for the purposes of spacing) when they follow
              a period.

       $ExpressionTimeLimit
              If set to a non-zero value n, than any expression that takes longer than  n  seconds  to  evaluate
              will  be  aborted  and  an error returned.  This is to prevent maliciously-crafted expressions for
              creating a denial-of-service.  In an included file, $ExpressionTimeLimit can only be lowered  from
              its  current  value.  In the top-level file, it can be set to any value, including zero to disable
              the time limit.

       $FirstIndent
              The number of spaces by which to indent the first line of a MSF-type reminder.  The default is 0.

       $FoldYear
              The standard Unix library functions may have difficulty dealing with dates later  than  2037.   If
              this  variable  is  set  to  1, then the UTC calculations "fold back" years later than 2037 before
              using the Unix library functions.  For example, to find out whether or not daylight saving time is
              in effect in June, 2077, the year is "folded back" to 2010, because both years begin on a  Monday,
              and  both are non-leapyears.  The rules for daylight saving time are thus presumed to be identical
              for both years, and the Unix library functions can handle 2010.  By default, this variable  is  0.
              Set it to 1 if the sun or UTC functions misbehave for years greater than 2037.

       $FormWidth
              The  maximum  width  of  each  line of text for formatting MSF-type reminders.  The default is the
              width of the terminal in columns, minus 8, but clamped at a minimum of 20 and a  maximum  of  500.
              If  standard  output  is not a terminal, then the default is 72.If an MSF-type reminder contains a
              word too long to fit in this width, it will not be truncated - the width limit will be ignored.

       $HushMode (read-only)
              If non-zero, then the -h option was supplied on the command line.

       $IgnoreOnce (read-only)
              If non-zero, then the -o option was supplied on the command line, or implicitly enabled  for  some
              other reason.  In this case, ONCE directives will be ignored.

       $InfDelta (read-only)
              If non-zero, then the -t option was supplied on the command line, with no n argument.

       $IntMax (read-only)
              The  largest  representable  INT.   On a machine with 32-bit signed integers using twos-complement
              representation, this will be 2147483647.

       $IntMin (read-only)
              The smallest representable INT.  On a machine with 32-bit signed  integers  using  twos-complement
              representation, this will be -2147483648.

       $Latitude (STRING type)
              The  latitude  of  your  location, expressed as a string that is a floating-point number.  Because
              Remind does not have a native floating-point type, we need to express it as a  string.   $Latitude
              can  range  from "-90.0" to "90.0", with positive numbers representing points north of the equator
              and negative numbers representing south.  Note that regardless of your locale, $Latitude is always
              interpreted in the "C" locale and as such, the decimal point must be a period (".").

       $Longitude (STRING type)
              The longitude of your location, expressed as a string that is a  floating-point  number.   Because
              Remind  does not have a native floating-point type, we need to express it as a string.  $Longitude
              can range from "-180.0" to  "180.0",  with  positive  numbers  representing  points  east  of  the
              Greenwich  Meridian  and negative numbers representing west.  Note that regardless of your locale,
              $Longitude is always interpreted in the "C" locale and as such, the decimal point must be a period
              (".").

              For example, the coordinates of the Statue of Liberty in New York City are approximately set by:

                  SET $Latitude   "40.68933"
                  SET $Longitude "-74.04454"

       $LatDeg, $LatMin, $LatSec (DEPRECATED)
              These specify the latitude of your location.  $LatDeg can range from -90 to  90,  and  the  others
              from  -59  to  59.   Northern  latitudes  are  positive; southern ones are negative.  For southern
              latitudes, all three components should be negative.  These three  variables  are  deprecated;  you
              should use $Latitude instead.

       $Location (STRING type)
              This  is  a  string  specifying the name of your location.  It is usually the name of your town or
              city.  It can be set to whatever you like, but  good  style  indicates  that  it  should  be  kept
              consistent with the latitude and longitude system variables.

       $LongDeg, $LongMin, $LongSec (DEPRECATED)
              These  specify  the  longitude  of  your  location.  $LongDeg can range from -180 to 180.  Western
              longitudes are positive; eastern ones are negative.  Note that all three  components  should  have
              the  same sign: All positive for western longitudes and all negative for eastern longitudes.  Note
              that for historical reasons, the sign for longitude is different from the  usual  convention!   If
              you  find the longitude of your location from a search engine, you will most likely need to invert
              the sign to have it work correctly with Remind. These three variables are deprecated;  you  should
              use  $Longitude  instead.   Note also that $Longitude uses the standard convention of negative for
              western longitudes and positive for eastern ones.

              The latitude and longitude information is required  for  the  functions  sunrise()  and  sunset().
              Default values can be compiled into Remind, or you can SET the correct values at the start of your
              reminder scripts.

              Note  that  setting any of $LongDec, $LongMin and $LongSec updates $Longitude correspondingly, and
              setting $Longitude updates $LongDeg, $LongMin and $LongSec.  Similar  rules  apply  to  $Latitude,
              $LatDeg, $LatMin and $LatSec.

       $MaxLateMinutes
              This  variable controls how Remind reacts to a computer being suspended and then woken.  Normally,
              if a timed reminder is queued and then the computer suspended, and  then  the  computer  is  woken
              after  the  timed  reminder's  trigger time, Remind will triger the timer anyway, despite the fact
              that the trigger time has already passed.

              If you set $MaxLateMinutes to a non-zero integer between 1 and 1440, then Remind will not  trigger
              a timed reminder whose trigger time is more than $MaxLateMinutes minutes in the past.

              Note  that Remind uses the value of $MaxLateMinutes that is in effect when it has finished reading
              the reminder file and puts itself in the background.  Generally, you  should  set  $MaxLateMinutes
              once near the beginning of the file and not change it after that.

       $MaxSatIter
              The maximum number of iterations for the SATISFY clause (described later.)  Must be at least 10.

       $MaxStringLen
              A limit on the longest string that Remind will allow you to create.  The default is 65535.  If you
              set $MaxStringLen to 0 or to -1, then remind will allow you to create arbitrarily-long strings, at
              least  until  it runs out of memory.  We do not recommend setting $MaxStringLen to 0 or -1 because
              it is very easy to write code that DOSes Remind in that case.

       $MinsFromUTC
              The number of minutes between Universal Time Coordinated and local time.  If $CalcUTC is non-zero,
              this is calculated upon startup of Remind.  Otherwise, you must set it explicitly.  If $CalcUTC is
              zero, then $MinsFromUTC is used in the astronomical calculations.  You must adjust it for daylight
              saving time yourself.  Also, if you want to initialize  $MinsFromUTC  using  the  -i  command-line
              option, you must also set $CalcUTC to 0 with the -i option.

       $NextMode (read-only)
              If non-zero, then the -n option was supplied on the command line.

       $MaxFullOmits (read-only)
              The maximum number of full OMITs allowed (a compiled-in constant.)

       $MaxPartialOmits (read-only)
              The maximum number of partial OMITs allowed (a compiled-in constant.)

       $NumFullOmits (read-only)
              The number of full OMITs in the current OMIT context.

       $NumPartialOmits (read-only)
              The number of partial OMITs in the current OMIT context.

       $NumQueued (read-only)
              Contains the number of reminders queued so far for background timed triggering.

       $NumTrig (read-only)
              Contains  the number of reminders triggered for the current date.  One use for this variable is as
              follows:  Suppose you wish to shade in the box of a PostScript  calendar  whenever  a  holiday  is
              triggered.   You could save the value of $NumTrig in a regular variable prior to executing a block
              of holiday reminders.  If the value of $NumTrig after the holiday block is greater than the  saved
              value,  then  at  least one holiday was triggered, and you can execute the command to shade in the
              calendar box.  (See the section "Calendar Mode".)

              Note that $NumTrig is affected only by REM commands; triggers in IFTRIG commands do not affect it.

       $OnceFile (STRING type)
              If you set this variable to a non-empty string, then rather than using the  file  access  date  to
              determine whether or not to run a ONCE-type reminder, Remind will maintain a timestamp in the file
              $OnceFile.  This is more reliable than using the access date of the reminder file.

              If  $OnceFile  does not exist, then it will be created the first time a ONCE keyword is processed.
              The file must be writable by the current user.  If you try to set $OnceFile after a ONCE  reminder
              has already been processed, Remind will issue a warning and ignore the attempt to set $OnceFile.

       $ParseUntriggered
              A  flag indicating whether or not Remind should fully parse REM statements that are not triggered.
              0 means to skip parsing them and 1 (the default) means to parse them.

              For example, if we have the following REM statement:

                          REM 2020-01-01 MSG ["bad_expression" * 2]

              Then by default, Remind will fully parse the line and issue a "Type mismatch" error  even  if  the
              reminder  is not triggered.  However, if $ParseUntriggered is set to 0, then Remind will not issue
              the error except on 2020-01-01, when the reminder is triggered.

              Setting $ParseUntriggered to 0 may in some cases slightly improve performance, at the risk of  not
              catching errors until a reminder is triggered.

       $PrefixLineNo (read-only)
              If non-zero, then the -l option was supplied on the command line.

       $PSCal (read-only)
              If non-zero, then the -p option was supplied on the command line.

       $RunOff (read-only)
              If non-zero, the RUN directives are disabled.

       $SimpleCal (read-only)
              Set to a non-zero value if either of the -p or -s command-line options was supplied.

       $SortByDate (read-only)
              Set to 0 if no -g option is used, 1 if sorting by date in ascending order, or 2 if sorting by date
              in descending order.

       $SortByPrio (read-only)
              Set  to 0 if no -g option is used, 1 if sorting by priority in ascending order, or 2 if sorting by
              priority in descending order.

       $SortByTime (read-only)
              Set to 0 if no -g option is used, 1 if sorting by time in ascending order, or 2 if sorting by time
              in descending order.

       $SubsIndent
              The number of spaces by which all lines (except the first)  of  an  MSF-type  reminder  should  be
              indented.  The default is 0.

       $SuppressLRM
              Normally,  when  Remind is run with the -c option in a UTF-8 locale, it emits a left-to-right mark
              sequence after printing day names or reminders.  Some terminals render this  incorrectly,  so  you
              can use:

                  SET $SuppressLRM 1

              at  the top of your reminder file to suppress the LRM sequences, or you can invoke Remind with the
              option '-i$SuppressLRM=1'.

       $SysInclude (read-only, STRING type)
              A directory path containing standard reminder scripts.  Currently, Remind ships with some standard
              holiday files and language packs.   The  value  of  $SysInclude  is  "/usr/share/remind"  on  this
              installation.

       $T (read-only, DATE type)
              Exactly equivalent to trigdate().  (See BUILT-IN FUNCTIONS.)

       $Td (read-only)
              Equivalent to day(trigdate()).

       $Tm (read-only)
              Equivalent to monnum(trigdate()).

       $Tw (read-only)
              Equivalent to wkdaynum(trigdate()).

       $Ty (read-only)
              Equivalent to year(trigdate()).

       $Tt (read-only, TIME type)
              Equivalent to trigtime().

       $TimeSep
              This  variable can be set only to ":" or ".".  It holds the character used to separate portions of
              a time when Remind prints a TIME or DATETIME value.

       $UntimedFirst (read-only)
              Set to 1 if the -g option is used with a fourth sort character of "d"; set to 0 otherwise.

       $U (read-only, DATE type)
              Exactly equivalent to today().  (See BUILT-IN FUNCTIONS.)

       $Ud (read-only)
              Equivalent to day(today()).

       $Um (read-only)
              Equivalent to monnum(today()).

       $Uw (read-only)
              Equivalent to wkdaynum(today()).

       $Uy (read-only)
              Equivalent to year(today()).

       $UseVTColors (read-only)
              Set to 1 if the -@ or -cc options were used; 0 otherwise.

       $UseBGVTColors (read-only)
              Set to 1 if the -@,,1 option was used; 0 otherwise.

       $Use256Colors (read-only)
              Set to 1 if the -@1 option was used; 0 otherwise.

       $UseTrueColors (read-only)
              Set to 1 if the -@2 option was used; 0 otherwise.

       $TerminalBackground (read-only)
              Returns -1 if the terminal background color could not be determined, 0 if it was found to be  dark
              (or  was specified as dark with the -@,0 option) or 1 if it was found to be light (or specified as
              light with the -@,1 option.)  The terminal background is considered to be "dark" if the average of
              the red, green and blue components is at most 85 out of 255, and if the maximum of  any  component
              is at most 128 out of 255.

       Note:   If  any of the calendar modes are in effect, then the values of $Daemon, $DontFork, $DontTrigAts,
       $DontQueue, $HushMode, $IgnoreOnce, $InfDelta, and $NextMode are not meaningful.

       BUILT-IN FUNCTIONS

       Remind has a plethora of built-in functions.  The syntax for a function call is the same as in  C  -  the
       function name, followed a comma-separated list of arguments in parentheses.  Function names are not case-
       sensitive.   If  a  function  takes  no  arguments,  it  must  be  followed by "()" in the function call.
       Otherwise, Remind will interpret it as a variable name, and probably not work correctly.

       In the descriptions below, short forms are used to  denote  acceptable  types  for  the  arguments.   The
       characters  "i",  "s",  "d",  "t"  and  "q"  denote  INT,  STRING,  DATE,  TIME  and  DATETIME arguments,
       respectively.  If an argument can be one of several types, the characters are concatenated.  For example,
       "di_arg" denotes an argument that can be a DATE or an INT.  "x_arg" denotes an argument that  can  be  of
       any type.  The type of the argument is followed by an underscore and an identifier naming the argument.

       The built-in functions are:

       abs(i_num)
              Returns the absolute value of num.

       access(s_file, si_mode)
              Tests  the  access  permissions  for the file file.  Mode can be a string, containing a mix of the
              characters "rwx" for read, write and execute permission testing.  Alternatively,  mode  can  be  a
              number  as described in the UNIX access(2) system call.  The function returns 0 if the file can be
              accessed with the specified mode, and -1 otherwise.

       adawn([dq_date])
              Returns the time of "astronomical dawn" on the specified date.  If date is  omitted,  defaults  to
              today().  If a datetime object is supplied, only the date component is used.

       adusk([dq_date])
              Returns  the  time of "astronomical twilight" on the specified date.  If date is omitted, defaults
              to today().

       ampm(tq_time [,s_am [,s_pm]])
              Returns a STRING that is the result of converting time (which is  either  a  TIME  or  a  DATETIME
              object)  to  "AM/PM" format.  The optional arguments am and pm are the strings to append in the AM
              and PM case, respectively; they default to "AM" and "PM".  The function obeys the system variables
              $DateSep, $TimeSep and $DateTimeSep when formatting its output.  For example:

                      ampm(0:22)                 returns "12:22AM"
                      ampm(17:45, "am", "pm")    returns "5:45pm"
                      ampm('2020-03-14@21:34')   returns "2020-03-14@9:34PM"

       ansicolor(i_red, i_green, i_blue [,i_bg [,i_clamp]])
              Returns a STRING that contains an ANSI escape sequence for changing the terminal text color.   The
              parameters  red,  green and blue are integers from 0 to 255 specifying the value of the respective
              color component.  As a special case, all three values can be -1, in which case the  ANSI  sequence
              "ESC[0m" is returned, which resets all text attributes to normal.

              The string returned by ansicolor depends on the color mode that Remind is running in, as specified
              by  the  -@ option.  If color mode is not enabled, then ansicolor always returns the empty string.
              Otherwise, it returns the escape sequence that best approximates the color  according  to  the  -@
              color mode.

              The  optional bg argument is either 0 or 1.  If 0 (the default), then the foreground color is set.
              If 1, then the background color is set.  Note that setting the  background  color  only  works  in
              256-color or true-color mode.

              The  optional  clamp  argument is either 0 or 1.  If 0 (the default), then colors are not adjusted
              based on the terminal background color.  If 1, then Remind  attempts  to  adjust  dark  or  bright
              colors so they have enough contrast to be visible in the terminal.

              The  first  three  arguments may alternatively be specified as a string consisting of three space-
              separated numbers, as in this example: "128 128 0"

              As a special case, ansicolor("")  is  equivalent  to  ansicolor(-1,-1,-1)  and  returns  the  ANSI
              sequence to reset all text attributes to normal.

              Note  that  inserting  ANSI  color  sequences  in  calendar  mode  will  produce  garbled results.
              Therefore, we recommend defining functions such as the ones below that return the empty string  in
              calendar mode:

                      IF $CalMode
                          FSET fg(r,g,b) ""
                          FSET bg(r,g,b) ""
                      ELSE
                          FSET fg(r,g,b) ansicolor(r,g,b)
                          FSET bg(r,g,b) ansicolor(r,g,b,1)
                      ENDIF
                      REM [fg(255,0,0)][bg(64,64,64)]Red on Gray[fg(-1,-1,-1)] in normal mode
                      REM SPECIAL COLOR 0 255 0 Green in normal and calendar mode

              If  you  use  the  ansicolor  function,  don't  forget  to  reset  the  color  back to normal with
              ansicolor(-1,-1,-1) or subsequent reminders will continue to be colored.

       args(s_fname)
              Returns the number of arguments expected by the user-defined function fname,  or  -1  if  no  such
              user-defined  function  exists.  Note that this function examines only user-defined functions, not
              built-in functions.  Its main use is  to  determine  whether  or  not  a  particular  user-defined
              function has been defined previously.  The args() function is available only in versions of Remind
              from 03.00.04 and up.

       asc(s_string)
              Returns  an  INT  that  is  the  ASCII  code of the first character in string.  As a special case,
              asc("") returns 0.  For UTF-8 strings, this will return the  UTF-8  byte  with  which  the  string
              begins,  which  is not likely to be very useful (and may indeed be negative on machines where char
              is a signed type.)

       baseyr()
              Returns the "base year" that was compiled into Remind  (normally  1990.)   All  dates  are  stored
              internally as the number of days since 1 January of baseyr().

       char(i_i1 [,i_i2...])
              This  function  can take any number of INT arguments.  It returns a STRING consisting of the bytes
              specified by the arguments.  It is easy to create invalid UTF-8 sequences; char does not check for
              this.  Note that none of the arguments can be 0, unless there is only one argument.  As a  special
              case, char(0) returns "".

       choose(i_index, x_arg1 [,x_arg2...])
              Choose  must  take  at least two arguments, the first of which is an INT.  If index is n, then the
              nth subsequent argument is returned.  If index is less than 1, then arg1 is returned.  If index is
              greater than the number of subsequent arguments, then the last argument is returned.  Examples:

                 choose(0, "foo", 1:13, 1000) returns "foo"
                 choose(1, "foo", 1:13, 1000) returns "foo"
                 choose(2, "foo", 1:13, 1000) returns 1:13
                 choose(3, "foo", 1:13, 1000) returns 1000
                 choose(4, "foo", 1:13, 1000) returns 1000
              Note that all arguments to choose() are always evaluated.

       coerce(s_type, x_arg)
              This function converts arg to the specified type, if such conversion is possible.   Type  must  be
              one of "INT", "STRING", "DATE", "TIME" or "DATETIME" (case-insensitive).  The conversion rules are
              as follows:

              If arg is already of the type specified, it is returned unchanged.

              If type is "STRING", then arg is converted to a string consisting of its printed representation.

              If  type  is "DATE", then an INT arg is converted by interpreting it as the number of days since 1
              January baseyr().  A STRING arg is converted by attempting to read it as  if  it  were  a  printed
              date.   A  DATETIME  is  converted to a date by dropping the time component.  A TIME arg cannot be
              converted to a date.

              If type is "TIME", then an INT arg is converted by interpreting it as the number of minutes  since
              midnight.   A  STRING  arg  is converted by attempting to read it as if it were a printed time.  A
              DATETIME is converted to a time by dropping the date component.  A DATE arg cannot be converted to
              a time.

              If type is "DATETIME", then an INT arg is converted by interpreting it as the  number  of  minutes
              since  midnight, 1 January baseyr().  A STRING is converted by attempting to read it as if it were
              a printed datetime.  Other types cannot be converted to a datetime.

              If type is "INT", then DATE, TIME and DATETIME  arguments  are  converted  using  the  reverse  of
              procedures described above.  A STRING arg is converted by parsing it as an integer.

       columns([s_arg])
              If  called  with  no arguments, columns() behaves as follows: If standard output is a TTY, returns
              the width of the terminal in columns.   If  standard  output  is  not  a  TTY,  attempts  to  open
              "/dev/tty" to obtain the terminal size.  If this fails, returns -1.

              If  called  with  a  single  string  argument, columns(str) returns the number of columns str will
              occupy if printed to a terminal.  ANSI color-changing sequences occupy zero columns  whereas  some
              Unicode characters occupy two columns.  columns(str) takes all of that into account.  Note that if
              Remind was compiled without Unicode support, columns(str) returns a type mismatch error.

       current()
              Returns  the current date and time as a DATETIME object.  This may be the actual date and time, or
              may be the date and time supplied on the command line.

       date(i_y, i_m, i_d)
              The date() function returns a DATE object with the year, month and day components specified by  y,
              m and d.

       datepart(dq_datetime)
              Returns a DATE object representing the date portion of datetime.

       datetime(args)
              The  datetime()  function  can  take  anywhere  from  two  to five arguments.  It always returns a
              DATETIME generated from its arguments.

              If you supply two arguments, the first must be a DATE and the second a TIME.

              If you supply three arguments, the first must be a DATE and the second and  third  must  be  INTs.
              The second and third arguments are interpreted as hours and minutes and converted to a TIME.

              If  you  supply  four  arguments, the first three must be INTs, interpreted as the year, month and
              day.  The fourth argument must be a TIME.

              Finally, if you supply five arguments, they must all be INTs and are interpreted as  year,  month,
              day, hour and minute.

       dawn([dq_date])
              Returns  the time of "civil dawn" on the specified date.  If date is omitted, defaults to today().
              If a datetime object is supplied, only the date component is used.

       day(dq_date)
              This function takes a DATE or DATETIME as an argument, and returns an INT that is the day-of-month
              component of date.

       daysinmon(i_m, i_y)
              Returns the number of days in month m (1-12) of the year y.

       defined(s_var)
              Returns 1 if the variable named by var is defined, or 0 if it is not.
              Note that defined() takes a STRING argument; thus, to check if variable X is defined, use:

                        defined("X")

              and not:

                        defined(X)

              The second example will attempt to evaluate X, and will return an error if it is undefined or  not
              of type STRING.

       dosubst(s_str [,d_date [,t_time]]) or dosubst(s_str [,q_datetime])
              Returns  a  STRING  that  is  the  result of passing str through the substitution filter described
              earlier.  The parameters date and time (or datetime) establish the effective trigger date and time
              used by the substitution filter.  If date and time are omitted, they default to today() and now().

              Note that if str does not end with "%", a newline character will  be  added  to  the  end  of  the
              result.   Also,  calling  dosubst() with a date that is in the past (i.e., if date < today()) will
              produce undefined results.

              Dosubst() is only available starting from version 03.00.04 of Remind.

       dusk([dq_date])
              Returns the time of "civil twilight" on the specified date.   If  date  is  omitted,  defaults  to
              today().

       easterdate([dqi_arg])
              If arg is an INT, then returns the date of Easter Sunday for the specified year.  If arg is a DATE
              or DATETIME, then returns the date of the next Easter Sunday on or after arg.  (The time component
              of a datetime is ignored.)  If arg is omitted, then it defaults to today().

              Note   that   easterdate  computes  the  Western  Easter.   For  the  Orthodox  Easter  date,  see
              orthodoxeaster.

       evaltrig(s_trigger [,dq_start])
              Evaluates trigger as if it were a REM or IFTRIG trigger specification and returns the trigger date
              as a DATE (or as a DATETIME if there is an AT clause.)  Returns a negative INT if no trigger could
              be computed.

              Normally, evaltrig finds a trigger date on or after today.  If you supply the start argument, then
              it scans starting from there.

              For example, the expression:

                evaltrig("Mon 1", '2008-10-07')

              returns '2008-11-03', since that is the first date on or after 7 October 2008 that satisfies  "Mon
              1".

              If  you want to see how many days it is from the first Monday in October, 2008 to the first Monday
              in November, 2008, use:

                evaltrig("Mon 1", '2008-11-01') - evaltrig("Mon 1", '2008-10-01')

              and the answer is 28.  The trigger argument to evaltrig can have all  the  usual  trigger  clauses
              (OMIT, AT, SKIP, etc.) but cannot have a SATISFY, MSG, etc. reminder-type clause.

       filedate(s_filename)
              Returns  the  modification date of filename.  If filename does not exist, or its modification date
              is before the year baseyr(), then 1 January of baseyr() is returned.

       filedatetime(s_filename)
              Returns the modification date  and  time  of  filename.   If  filename  does  not  exist,  or  its
              modification date is before the year baseyr(), then midnight, 1 January of baseyr() is returned.

       filedir()
              Returns  the  directory  that  contains the current file being processed.  It may be a relative or
              absolute pathname, but is guaranteed to be correct for use in an INCLUDE command as follows:

                 INCLUDE [filedir()]/stuff

              This includes the file "stuff" in the same directory as the current file  being  processed.   Note
              that this workaround is no longer necessary because DO stuff will achieve the same goal.

              Note  that  if  the  currently-processing  reminders  file  was specified as a symbolic link, then
              filedir() returns the directory containing the symbolic link and not the directory containing  the
              target  of  the  symbolic  link.   You  should avoid using symbolic links to files unless both the
              symbolic link and its target happen to be in the same directory.

       filename()
              Returns (as a STRING) the name of the current file being processed  by  Remind.   Inside  included
              files, returns the name of the included file.

       getenv(s_envvar)
              Similar  to  the  getenv(2) system call.  Returns a string representing the value of the specified
              environment variable.  Returns "" if the environment variable is not defined.  Note that the names
              of environment variables are generally case-sensitive; thus, getenv("HOME") is  not  the  same  as
              getenv("home").

       hebdate(i_day, s_hebmon [,idq_yrstart [,i_jahr [,i_aflag]]])
              Support for Hebrew dates - see the section "THE HEBREW CALENDAR"

       hebday(dq_date)
              Support for Hebrew dates - see the section "THE HEBREW CALENDAR"

       hebmon(dq_date)
              Support for Hebrew dates - see the section "THE HEBREW CALENDAR"

       hebyear(dq_date)
              Support for Hebrew dates - see the section "THE HEBREW CALENDAR"

       hour(tq_time)
              Returns the hour component of time.

       htmlescape(s_str)
              Returns  a modified copy of str where "<" is replaced with "&lt;"; ">" is replaced with "&gt;" and
              "&" is replaced with "&amp;"

       htmlstriptags(s_str)
              Returns a modified copy of str where HTML tags are  stripped  out.   The  stripping  algorithm  is
              fairly  naive;  the  function  starts  stripping  characters when it encounters a "<" and it stops
              stripping when it encounters a ">".

       iif(si_test1, x_arg1, [si_test2, x_arg2,...], x_default)
              If test1 is not zero or the null string, returns arg1.  Otherwise, if test2 is  not  zero  or  the
              null  string,  returns  arg2, and so on.  If all of the test arguments are false, returns default.
              Note that all arguments are always evaluated.  This function accepts an odd number of arguments  -
              note  that  prior  to  version  03.00.05  of Remind, it accepted 3 arguments only.  The 3-argument
              version of iif() is compatible with previous versions of Remind.

       index(s_search, s_target [,i_start)
              Returns an INT that is the location of target in the string search.   The  first  character  of  a
              string is numbered 1.  If target does not exist in search, then 0 is returned.

              The  optional  parameter  start  specifies  the  position  in search at which to start looking for
              target.

       isany(arg1 [,arg2, ..., argN]);
              Returns 1 if the first argument arg1 is equal to any of  the  subsequent  arguments  arg2  through
              argN; returns 0 otherwise.  Also returns 0 if called with only one argument.

              As an example, the following two expressions are equivalent:

                      (a == b) || (a == c) || (a == d) || (a == e)

                      isany(a, b, c, d, e)

       isdst([d_date [,t_time]]) or isdst(q_datetime)
              Returns  a  positive  number  if daylight saving time is in effect on the specified date and time.
              Date defaults to today() and time defaults to midnight.

              Note that this function is only as reliable as the C run-time library functions.  It is  available
              starting with version 03.00.07 of Remind.

       isleap(idq_arg)
              Returns 1 if arg is a leap year, and 0 otherwise.  Arg can be an INT, DATE or DATETIME object.  If
              a DATE or DATETIME is supplied, then the year component is used in the test.

       isomitted(dq_date)
              Returns  1 if date is omitted, given the current global OMIT context.  Returns 0 otherwise.  (If a
              datetime is supplied, only the date part is used.)  Note that any local OMIT or  OMITFUNC  clauses
              are not taken into account by this function.

       language()
              Returns  a STRING naming the language supported by Remind.  (See "SUPPORT FOR OTHER LANGUAGES") By
              default, Remind is compiled to support English messages, so this function returns "English".   For
              other  languages,  this function will return the English name of the language (e.g. "German") Note
              that language() is not available in versions of Remind prior to 03.00.02.

       localtoutc(q_datetime)
              Given a DATETIME object interpreted in  the  local  time  zone,  return  a  DATETIME  object  that
              expresses the same time in UTC.

       lower(s_string)
              Returns a STRING with all upper-case characters in string converted to lower-case.

       max(x_arg1 [,x_arg2...)
              Can  take any number of arguments, and returns the maximum.  The arguments can be of any type, but
              must all be of the same type.  They are compared as with the > operator.

       min(x_arg1 [,x_arg2...)
              Can take any number of arguments, and returns the minimum.  The arguments can be of any type,  but
              must all be of the same type.  They are compared as with the < operator.

       minsfromutc([d_date [,t_time]]) or minsfromutc(q_datetime)
              Returns  the number of minutes from Universal Time Coordinated (formerly GMT) to local time on the
              specified date and time.  Date defaults to today() and time defaults to midnight.  If  local  time
              is before UTC, the result is negative.  Otherwise, the result is positive.

              Note  that this function is only as reliable as the C run-time library functions.  It is available
              starting with version 03.00.07 of Remind.

       minute(tq_time)
              Returns the minute component of time.

       mon(dqi_arg)
              If arg is of DATE or DATETIME type, returns a string that names the month component of  the  date.
              If arg is an INT from 1 to 12, returns a string that names the month.

       monnum(dq_date)
              Returns an INT from 1 to 12, representing the month component of date.

       moondate(i_phase [,d_date [,t_time]]) or moondate(i_phase, q_datetime)
              This  function returns the date of the first occurrence of the phase phase of the moon on or after
              date and time.  Phase can range from 0 to 3, with 0 signifying new moon, 1 first quarter,  2  full
              moon,  and  3  third quarter.  If date is omitted, it defaults to today().  If time is omitted, it
              defaults to midnight.

              For example, the following returns the date of the next full moon:

                        SET fullmoon moondate(2)

       moontime(i_phase [,d_date [,t_time]]) or moontime(i_phase, q_datetime)
              This function returns the time of the first occurrence of the phase phase of the moon on or  after
              date  and  time.  Phase can range from 0 to 3, with 0 signifying new moon, 1 first quarter, 2 full
              moon, and 3 third quarter.  If date is omitted, it defaults to today().  If time  is  omitted,  it
              defaults  to  midnight.   Moontime()  is  intended to be used in conjunction with moondate().  The
              moondate() and moontime() functions are accurate to within a couple of minutes  of  the  times  in
              "Old Farmer's Almanac" for Ottawa, Ontario.

              For example, the following returns the date and time of the next full moon:

                        MSG Next full moon at [moontime(2)] on [moondate(2)]

       moondatetime(i_phase [,d_date [,t_time]]) or moondatetime(i_phase, q_datetime)
              This function is similar to moondate and moontime, but returns a DATETIME result.

       moonphase([d_date [,t_time]]) or moonphase(q_datetime)
              This  function  returns  the  phase  of  the  moon  on date and time, which default to today() and
              midnight, respectively.  The returned value is an integer from 0 to 359, representing the phase of
              the moon in degrees.  0 is a new moon, 180 is a full moon, 90 is first-quarter, etc.

       multitrig(s_trig1 [,s_trig2, [... s_trigN]])
              multitrig evaluates each string as a trigger,  similar  to  evaltrig,  and  returns  the  earliest
              trigger  date  that  is  on  or after today().  multitrig is similar to trig but has the following
              difference:

              trig returns the first trigger date that would have triggered today, whereas multitrig returns the
              earliest trigger date later than today, regardless of whether it would have triggered today.

              If no trigger can be computed that is later than today(), then multitrig returns 1990-01-01.

              Consider the following examples, assuming that today is Sunday, 24 March 2024:

                 # Returns 1990-01-01 because neither would trigger today
                 SET a trig("Mon", "Wed")

                 # Returns 2024-03-25 because it's the earlier trigger date
                 SET a multitrig("Mon", "Wed")

                 # Returns 2024-03-27 because it's the first that would trigger today
                 SET a trig("Wed +3", "Mon +3")

                 # Returns 2024-03-25 because it's the earlier trigger date
                 SET a multitrig("Wed +3", "Mon +3")

                 # Returns 1990-01-01 because all triggers have expired
                 SET a multitrig("2000", "2022", "1998", "2023")

              In general, multitrig works better with the Remind algorithm than trig and should be used most  of
              the time.  As an example, this reminder is issued at the end of each quarter:

                  REM [multitrig("Mar 31", "Jun 30", "Sep 30", "Dec 31")] +7 MSG \
                  %"End of [ord($Tm/3)] quarter%" is %b.

              If you want the last working day of each quarter, you could use:

                  PUSH-OMIT-CONTEXT
                  OMIT Sat Sun
                  REM [multitrig("Mar ~1", "Jun ~1", "Sep ~1", "Dec ~1")] +7 MSG \
                  %"Last working day of [ord($Tm/3)] quarter%" is %b.
                  POP-OMIT-CONTEXT

              Note  that unlike evaltrig, multitrig always returns a DATE and never a DATETIME.  Including an AT
              clause in a trigger supplied to multitrig will result in an error.

       ndawn([dq_date])
              Returns the time of "nautical dawn" on the specified  date.   If  date  is  omitted,  defaults  to
              today().  If a datetime object is supplied, only the date component is used.

       ndusk([dq_date])
              Returns  the  time  of "nautical twilight" on the specified date.  If date is omitted, defaults to
              today().

       nonomitted(dq_start, dq_end [, i_step] [,s_wkday...])
              This function returns the number of non-omitted days between start and  end.   If  start  is  non-
              omitted, then it is counted.  end is never counted.

              Note  that  if  end  is less than start, the arguments are effectively swapped, so counting always
              begins from the older date.

              If the third argument to nonomitted is an INT, then it must be greater than zero, and is  consider
              to be the step by which nonomitted counts.  For example the following expression:

                      nonomitted('2023-07-01', '2023-07-29', 7)

              returns  the number of non-omitted Saturdays from 2023-07-01 up to (but not including) 2023-07-29.
              (Both 2023-07-01 and 2023-07-29 are Saturdays.)

              If no step argument is supplied, then a step of 1 is used.

              In addition to using the global OMIT context, you can supply additional arguments that  are  names
              of weekdays to be omitted.  However, in a REM command, any local OMITFUNC clause is not taken into
              account by this function.

              For example, the following line sets a to 11 (assuming no global OMITs):

                   set a nonomitted('2007-08-01', '2007-08-16', "Sat", "Sun")

              because  Thursday, 16 August 2007 is the 11th working day (not counting Saturday and Sunday) after
              Wednesday, 1 August 2007.

              nonomitted has various uses.  For example, many schools run on a six-day cycle and the day  number
              is  not  incremented  on holidays.  Suppose the school year starts with Day 1 on 4 September 2007.
              The following reminder will label day numbers in a calendar:

                 IF today() >= '2007-09-04'
                     set daynum nonomitted('2007-09-04', today(), "Sat", "Sun")
                     REM OMIT SAT SUN SKIP CAL Day [(daynum % 6) + 1]
                 ENDIF

              Obviously, the answer you get from nonomitted depends on the global  OMIT  context.   If  you  use
              movable OMITs, you may get inconsistent results.

              Here  is  a more complex use for nonomitted.  My garbage collection follows two interleaved 14-day
              cycles: One Friday, garbage and paper recycling ("Black Box") are  collected.   The  next  Friday,
              garbage  and  plastic recycling ("Blue Box") are collected.  If any of Monday-Friday is a holiday,
              collection is delayed until the Saturday.  Here's a way to encode these rules:

                 fset _garbhol(x) wkdaynum(x) == 5 && nonomitted(x-4, x+1) < 5
                 REM 12 November 1999 *14 AFTER OMITFUNC _garbhol MSG Black Box
                 REM 19 November 1999 *14 AFTER OMITFUNC _garbhol MSG Blue Box

              Here's how it works:  The _garbhol(x) user-defined function returns 1 if and only if (1)  x  is  a
              Friday  and (2) there is at least one OMITted day from the previous Monday up to and including the
              Friday.

              The first REM statement sets up the 14-day black-box cycle.   The  AFTER  keyword  makes  it  move
              collection  to  the  Saturday  if _garbhol returns 1.  The second REM statement sets up the 14-day
              blue-box cycle with a similar adjustment made by AFTER in conjunction with _garbhol.

       now()  Returns the current system time, as a TIME type.  This may be the actual time, or a time  supplied
              on the command line.

       ord(i_num)
              Returns  a string that is the ordinal number num.  For example, ord(2) returns "2nd", and ord(213)
              returns "213th".

       orthodoxeaster([dqi_arg])
              If arg is an INT, then returns the date of Orthodox Easter Sunday for the specified year.  If  arg
              is  a  DATE or DATETIME, then returns the date of the next Orthodox Easter Sunday on or after arg.
              (The time component of a datetime is ignored.)  If arg is omitted, then it defaults to today().

              Note that orthodoxeaster  computes  the  Orthodox  Easter.   For  the  Western  Easter  date,  see
              easterdate.

       ostype()
              Returns "UNIX".  Remind used to run on OS/2 and MS-DOS, but does not any longer.

       pad(x_arg, s_padstr, i_len [, i_right])
              Converts  the  first  argument  arg  to  a string if necessary, and then if it is shorter than len
              characters, pads to to len characters using as many copies (including partial copies) of padstr as
              necessary.  By default, the string is left-padded, but if right  is  supplied  and  non-zero,  the
              string will be right-padded.

              Here are some examples:

                  pad(3, "0", 2)        -->  "03"
                  pad(465, "0", 2)      -->  "465"
                  pad("foo", " ", 5)    -->  "  foo"
                  pad("foo", " ", 5, 1) -->  "foo  "
                  pad("foo", "bar", 11) -->  "barbarbafoo"

       plural(i_num [,s_str1 [,s_str2]])
              Can  take  from one to three arguments.  If one argument is supplied, returns "s" if num is not 1,
              and "" if num is 1.

              If two arguments are supplied, returns str1 + "s" if num is not 1.  Otherwise, returns str1.

              If three arguments are supplied, returns str1 if num is 1, and str2 otherwise.

       psmoon(i_phase [,i_size [,s_note [,i_notesize]]])
              [DEPRECATED] Returns a STRING consisting of PostScript code to draw a moon in the upper-left  hand
              corner  of the calendar box.  Phase specifies the phase of the moon, and is 0 (new moon), 1 (first
              quarter), 2 (full moon) or 3 (third quarter).  If size is specified, it controls the radius of the
              moon in PostScript units (1/72 inch.)  If it is not specified or is negative, the size of the day-
              number font is used.

              For example, the following four lines place moon symbols on the PostScript calendar:

                        REM [moondate(0)] PS [psmoon(0)]
                        REM [moondate(1)] PS [psmoon(1)]
                        REM [moondate(2)] PS [psmoon(2)]
                        REM [moondate(3)] PS [psmoon(3)]

              If note is specified, the text is used to annotate the moon display.  The font is  the  same  font
              used  for  calendar  entries.   If  notesize  is  given, it specifies the font size to use for the
              annotation, in PostScript units (1/72 inch.)  If notesize is not given, it defaults  to  the  size
              used  for  calendar  entries.   (If  you annotate the display, be careful not to overwrite the day
              number -- Remind does not check for this.)  For example, if you want the time  of  each  new  moon
              displayed, you could use this in your reminder script:

                   REM [moondate(0)] PS [psmoon(0, -1, moontime(0)+"")]

              Note how the time is coerced to a string by concatenating the null string.

       psshade(i_gray) or psshade(i_red, i_green, i_blue)
              [DEPRECATED]  Returns  a STRING that consists of PostScript commands to shade a calendar box.  Num
              can range from 0 (completely black) to 100 (completely white.)  If three arguments are given, they
              specify red, green and blue intensity from 0 to 100.  Here's an example of how to use this:

                        REM Sat Sun PS [psshade(95)]

              The above command emits PostScript code to lightly shade the boxes for Saturday and  Sunday  in  a
              PostScript calendar.

              Note  that psmoon and psshade are deprecated; instead you should use the SPECIAL SHADE and SPECIAL
              MOON reminders as described in "Out-of-Band Reminders."

       realcurrent()
              Returns (as a DATETIME) the true date and time of day as provided by the operating  system.   This
              is in contrast to current(), which may return a time supplied on the command line.

       realnow()
              Returns  the  true time of day as provided by the operating system.  This is in contrast to now(),
              which may return a time supplied on the command line.

       realtoday()
              Returns the date as provided by the operating system.  This is in contrast to Remind's concept  of
              "today", which may be changed if it is running in calendar mode, or if a date has been supplied on
              the command line.

       rows() If  standard  output  is a TTY, returns the height of the terminal in rows.  If standard output is
              not a TTY, attempts to open "/dev/tty" to obtain the terminal size.  If this fails, returns -1.

       sgn(i_num)
              Returns -1 if num is negative, 1 if num is positive, and 0 if num is zero.

       shell(s_cmd [,i_maxlen])
              Executes cmd as a system command, and returns the first 511 characters of  output  resulting  from
              cmd.   Any  whitespace  character in the output is converted to a space.  Note that if RUN OFF has
              been executed, or the -r command-line option has been used, shell() will result in an  error,  and
              cmd will not be executed.

              If  maxlen  is  specified, then shell() returns the first maxlen characters of output (rather than
              the first 511).  If maxlen is specified as a negative number, then it defaults to the value of the
              system variable $MaxStringLen.

       shellescape(s_str)
              Returns str with all shell metacharacters such as " ", "*", etc escaped  with  a  backslash.   For
              example:

               SET a shellescape("a b*? c&d$e")

              will set a to:

               "a\ b\*\?\ c\&d\$e"

       slide(d_start, i_amt [, i_step] [,s_wkday...])
              This  function  is  the inverse of nonomitted.  It adds amt (which can be negative) chunks of step
              days to start, not counting omitted days.  If step is not supplied, then it is assumed  to  be  1.
              Note  that  only every stepth day is tested to see if it is omitted.  The optional wkday arguments
              are additional weekday names to omit.

              Consider this example:

                   OMIT 14 May 2009
                   SET a slide('2009-05-13', 5, "Sat", "Sun")

              In this case, a is set to 2009-05-21.  That's because we slide forward by 5  days,  not  including
              Thursday, May 14 or Saturday and Sunday, May 16 and 17.  You can go backwards, too, so:

                   OMIT 14 May 2009
                   SET a slide('2009-05-21', -5, "Sat", "Sun")

              takes a back to 2009-05-13.

              Now consider this example:

                      OMIT 14 May 2009
                      SET a slide('2009-05-07', 2, 7)

              This  sets a to '2009-05-28' because we skip ahead two weeks, not counting a week where the day we
              land on happens to be omitted.  Contrast with this:

                      OMIT 13 May 2009
                      SET a slide('2009-05-07', 2, 7)

              which sets a to '2009-05-21'.  Although 2009-05-13 is omitted, we don't "land" on it  as  we  step
              forward in chunks of 7 days, so we never see that it is omitted.

       soleq(i_which [, dqi_start])
              The  soleq function computes solstices and equinoxes.  The which parameter ranges from 0 to 3, and
              specifies which event we are interested in: 0 is the March equinox; 1 is the June solstice;  2  is
              the September equinox and 3 is the December solstice.

              The  optional  start  parameter  can  either be an integer specifying the year of the event we are
              interested in, or a DATE or DATETIME object; if the latter, then soleq returns the first event  on
              or  after  the  date  part  of  the  start  parameter (it ignores the time component if start is a
              DATETIME.)  If start is not supplied, then it defaults to today().

              The return value of soleq() is a DATETIME object specifying the date and time of the  solstice  or
              equinox  in  the  local  time  zone.  It should be accurate to within 3 minutes or so in the worst
              case.

              See the included file $SysInclude/seasons.rem for examples of how to use soleq().

       stdout()
              Returns a string representing where Remind's standard output is going.  The return values are  one
              of the following: "TTY" if standard-output is a terminal, "BLOCKDEV" if it is a block device (very
              unlikely), "CHARDEV" if it is a character device (eg, /dev/null), "DIR" if it is a directory (very
              unlikely),  "PIPE" if it is a pipe or FIFO, "SYMLINK" if it is a symlink (very unlikely), "SOCKET"
              if it is a socket, or "UNKNOWN" if it could not be determined.

              The purpose of stdout() is mostly to distinguish between TTY and non-TTY output; you may  wish  to
              change or disable colors if the output is not going to a TTY.

       strlen(s_str)
              Returns  the length of str.  If the length of str is too large to represent as an integer, emits a
              "Number too high" error.

       substr(s_str, i_start [,i_end])
              Returns a STRING consisting of all  characters  in  str  from  start  up  to  and  including  end.
              Characters are numbered from 1.  If end is not supplied, then it defaults to the length of str.

       sunrise([dq_date])
              Returns  a  TIME  indicating the time of sunrise on the specified date (default today().)  In high
              latitudes, there may be no sunrise on a particular day, in which case sunrise() returns the INT  0
              if the sun never sets, or 1440 if it never rises.

       sunset([dq_date])
              Returns  a  TIME  indicating  the time of sunset on the specified date (default today().)  In high
              latitudes, there may be no sunset on a particular day, in which case sunset() returns the INT 0 if
              the sun never rises, or 1440 if it never sets.

              The functions sunrise() and sunset() are based on an algorithm in "Almanac for Computers  for  the
              year  1978"  by  L.  E.  Doggett,  Nautical  Almanac  Office, USNO.  They require the latitude and
              longitude to be specified by setting the appropriate system variables.  (See "System  Variables".)
              The  sun  functions  should  be  accurate  to  within  about 4 minutes for latitudes lower than 60
              degrees.  The functions are available starting from version 03.00.07 of Remind.

       time(i_hr, i_min)
              Creates a TIME with the hour and minute components specified by hr and min.

       timepart(tq_datetime)
              Returns a TIME object representing the time portion of datetime.

       timezone([dq_datetime])
              Returns a string representing the local time zone name of the given DATETIME.  If no  argument  is
              supplied,  Remind uses the value of current().  If a DATE rather than DATETIME is supplied, Remind
              uses a time part of 00:00.

       today()
              Returns Remind's notion of "today."  This may be the actual system date, or a date supplied on the
              command line, or the date of the calendar entry currently being computed.

       trig(s_1 [,s_2, ...])
              For each string argument s_n,  trig  evaluates  s_n  as  if  it  were  a  REM  or  IFTRIG  trigger
              specification.   If  the  trigger  would  trigger  today, then the trigger date is returned and no
              further triggers are evaluated.  If none of the triggers would trigger today, then the  zero  date
              1990-01-01 is returned.
              trig also has a zero-argument form; this returns the trigger date of the most recent trig function
              that returned a non-zero trigger date.

              trig can be used to make more sophisticated versions of IFTRIG.  For example, if you have meetings
              every Monday in June and July, and you want warnings 3 days in advance, you could use:

                  REM [trig("Mon Jun +3", "Mon July +3")] +3 MSG Meeting %b

              NOTE:  We  need  to  repeat  the +3 delta outside of the trig function for advance warning to work
              properly.  This is because trig returns a date constant (the trigger date)  and  the  REM  command
              does not know the details of trig's arguments.

              Note that because Remind has short-circuit logical operators, something like:

                  SET a trig("Mon +7") || trig("Fri +7")

              would  set the value of trig() to the date of the following Monday.  Because trig("Mon +7") always
              returns true, the logical-OR operator does not bother evaluating trig("Fri  +7")  which  therefore
              does not set trig().

              Important  Note:  Because trig() always returns an absolute date, it will not work properly with a
              SATISFY clause.  Consider this reminder:

                  REM [trig("Mar", "Apr")] SATISFY [$Td == 15] MSG 15 Mar or April

              If we run Remind on 5 March 2022, we might expect the trigger date to be calculated  as  15  March
              2022...  but  that's  not  what  happens.   Instead,  the trig function is evaluated first, and it
              returns 2022-03-05.  So as far as Remind is concerned, the REM statement becomes:

                  REM 2022-03-05 SATISFY [$Td == 15] MSG 15 Mar or April

              and the SATISFY expression is never true.  So: Do not mix trig() and SATISFY.

       trigdate()
              Returns the calculated trigger date of the last REM or IFTRIG command.  If used in the body  of  a
              REM  command, returns that command's trigger date.  If the most recent REM command did not yield a
              computable trigger date, returns the integer 0.

       trigdatetime()
              Similar to trigdate(), but returns a DATETIME if the most recent triggerable REM command had an AT
              clause.  If there was no AT clause, returns a DATE.  If no trigger could be computed, returns  the
              integer 0.  See "MULTI-DAY EVENTS" for more information.

       trigeventstart()
              Returns  a  DATETIME representing the start of the most recent triggerable REM command that had an
              AT clause.  For events without a DURATION or that do not span multiple days, returns the  same  as
              trigdatetime().  If the REM command did not have an AT clause, returns the integer -1 (and differs
              from trigdatetime() in this respect.)  See "MULTI-DAY EVENTS" for more information.

       trigeventduration()
              Returns a TIME representing the duration of the most recent triggerable REM command that had an AT
              and  a  DURATION  clause.   If  the  event  does not span multiple days, returns the same thing as
              trigduration().  If the REM command lacked an AT or DURATION clause, returns -1.   See  "MULTI-DAY
              EVENTS" for more information.

       trigback()
              Returns  the "back" amount of the last REM or IFTRIG command.  Returns a positive integer N if the
              "back" is of the form -N, or a negative integer if it is of the form --N.  If there is no  "back",
              then returns 0.

       trigdelta()
              Returns the "delta" amount of the last REM or IFTRIG command.  Returns a positive integer N if the
              "delta"  is  of  the  form  +N,  or  a  negative integer if it is of the form ++N.  If there is no
              "delta", then returns 0.

       trigtimedelta()
              Similar to trigdelta(), but returns the delta used in the AT clause of a timed reminder.

       trigrep()
              Returns the "repeat" amount of the last REM or IFTRIG command.  Returns a positive  integer  N  if
              the "repeat" is of the form *N.  If there is no "repeat", then returns 0.

       trigtimerep()
              Similar to trigrep(), but returns the repeat used in the AT clause of a timed reminder.

       trigduration()
              Returns  (as  a  TIME  type)  the DURATION parameter of a timed reminder.  If there is no DURATION
              parameter, returns the integer -1.  See "MULTI-DAY EVENTS" for more information.

       trigpriority()
              Returns the PRIORITY of the last REM or IFTRIG command.

       triguntil()
              Returns (as a DATE type) the UNTIL parameter of the last REM or IFTRIG command.  If there  was  no
              UNTIL  parameter,  returns the integer -1.  If there is a THROUGH parameter, that will be returned
              by triguntil() since "THROUGH yyyy-mm-dd" is simply syntactic sugar for "*1 UNTIL yyyy-mm-dd".

       trigscanfrom()
              Returns (as a DATE type) the SCANFROM parameter of the last REM or IFTRIG command.  If  there  was
              no  SCANFROM  parameter, returns the integer -1.  Note that FROM and SCANFROM interact; a reminder
              that has a "FROM yyyy-mm-dd" parameter will act as if it has a SCANFROM parameter whose  value  is
              the maximum of "yyyy-mm-dd" and today.

       trigfrom()
              Returns  (as  a  DATE type) the FROM parameter of the last REM or IFTRIG command.  If there was no
              FROM parameter, returns the integer -1.

       trigger(d_date [,t_time [,i_utcflag]]) or trigger(q_datetime [,i_utcflag])
              Returns a string suitable for use in a REM command or a SCANFROM or UNTIL clause, allowing you  to
              calculate trigger dates in advance.  Note that in earlier versions of Remind, trigger was required
              to  convert  a  date  into  something  the REM command could consume.  However, in this version of
              Remind, you can omit it.  Note that trigger() always returns its result in English, even for  non-
              English  versions of Remind.  Normally, the date and time are the local date and time; however, if
              utcflag is non-zero, the date and time are interpreted as UTC times, and are  converted  to  local
              time.  Examples:

                   trigger('1993/04/01')

              returns "1 April 1993",

                   trigger('1994/08/09', 12:33)

              returns "9 August 1994 AT 12:33", as does:

                   trigger('1994/08/09@12:33').

              Finally:

                   trigger('1994/12/01', 03:00, 1)

              returns "30 November 1994 AT 22:00" for EST, which is 5 hours behind UTC.  The value for your time
              zone may differ.

       trigtags()
              Returns  a  comma-separated  list of the TAGs associated with the most recent REM command that was
              triggered.  Returns the empty string if there were no TAGs.  If there are multiple tags, they  are
              each separated by a single comma, not a comma and a space.

       trigtime()
              Returns  the  time  of the last REM command with an AT clause.  If the last REM did not have an AT
              clause, returns the integer 0.  If a REM command has an AT clause with a DURATION,  then  you  can
              compute the end time as trigtime() + trigduration().

       trigvalid()
              Returns  1  if  the  value  returned  by trigdate() is valid for the most recent REM command, or 0
              otherwise.  Sometimes REM commands cannot calculate a trigger date.  For  example,  the  following
              REM command can never be triggered:

                 REM Mon OMIT Mon SKIP MSG Impossible!

       typeof(x_arg)
              Returns "STRING", "INT", "DATE", "TIME" or "DATETIME", depending on the type of arg.

       tzconvert(q_datetime, s_srczone [,s_dstzone])
              Converts  datetime  from  the  time  zone  named by srczone to the time zone named by dstzone.  If
              dstzone is omitted, the default system time zone is used.  The return value is a  DATETIME.   Time
              zone  names  are  system-dependent;  consult  your  operating system for legal values.  Here is an
              example:

           tzconvert('2007-07-08@01:14', "Canada/Eastern", "Canada/Pacific")

                 returns

           2007-07-07@22:14

       upper(s_string)
              Returns a STRING with all lower-case characters in string converted to upper-case.

       utctolocal(q_datetime)
              Given a DATETIME object interpreted in UTC, return a DATETIME object that expresses the same  time
              in the local time zone.

       value(s_varname [,x_default])
              Returns  the  value  of  the specified variable.  For example, value("X"+"Y") returns the value of
              variable XY, if it is defined.  If XY is not defined, an error results.

              However, if you supply a second argument, it is returned if  the  varname  is  not  defined.   The
              expression  value("XY",  0)  will  return  0  if  XY  is not defined, and the value of XY if it is
              defined.

       version()
              Returns a string specifying the version of Remind.  For version 05.00.02, returns "05.00.02".   It
              is  guaranteed  that  as new versions of Remind are released, the value returned by version() will
              strictly increase, according to the rules for string ordering.

       weekno([dq_date, [i_wkstart, [i_daystart]]])
              Returns the week number of the year.  If no arguments are supplied,  returns  the  ISO  8601  week
              number  for  today().  If one argument date is supplied, then returns the ISO 8601 week number for
              that date.  If two arguments are supplied, then wkstart must range from 0 to 6, and represents the
              first day of the week (with 0 being Sunday and 6 being Saturday.).  If wkstart  is  not  supplied,
              then  it defaults to 1.  If the third argument daystart is supplied, then it specifies when Week 1
              starts.  If daystart is less than or equal to 7, then Week 1 starts on the  first  wkstart  on  or
              after  January  daystart.   Otherwise,  Week  1  starts  on the first wkstart on or after December
              daystart.  If omitted, daystart defaults to 29 (following the ISO 8601 definition.)

       wkday(dqi_arg)
              If arg is a DATE or DATETIME, returns a string representing the day of the week of the  date.   If
              arg is an INT from 0 to 6, returns the corresponding weekday ("Sunday" to "Saturday").

       wkdaynum(dq_date)
              Returns  a  number  from 0 to 6 representing the day-of-week of the specified date.  (0 represents
              Sunday, and 6 represents Saturday.)

       year(dq_date)
              Returns a INT that is the year component of date.

MULTI-DAY EVENTS

       If you specify a start time with AT and a duration  with  DURATION,  you  can  create  events  that  span
       multiple days.  Consider these two REM statements:

           REM 1991-02-13 AT 16:00 DURATION 72:00 MSG 72-hour event
           REM 1991-02-13 THROUGH 1991-02-16 AT 16:00 MSG Four events

       The  first  statement creates a single event that starts on 13 February 1991 at 16:00 and runs through 16
       February 1991 at 16:00

       The second statements creates four separate events that start at 16:00 on 13, 14, 15 and 16 February 1991
       and have indefinite duration.

       Remind handles multi-day events specially.  These are the rules:

       On the first day of a multi-day event, trigdatetime() will return the  starting  date  and  time  of  the
       event, and trigduration() will return the original DURATION.

       On  each subsequent day of a multi-day event, trigdatetime() will return midnight on the day in question,
       and trigduration() will return the remaining duration.  Consider this example:

           #!/bin/sh
           remind - 12 feb 1991 '*6' <<'EOF'
           BANNER %
           REM 1991-02-13 AT 16:00 DURATION 72:00 SATISFY 1
           set a trigdatetime()
           set b trigduration()
           set c trigeventstart()
           set d trigeventduration()
           MSG now=[today()] dt=[a] dur=[b] estart=[c] edur=[d]%
           EOF

       The output is:

       now=1991-02-12 dt=1991-02-13@16:00 dur=72:00 estart=1991-02-13@16:00 edur=72:00
       now=1991-02-13 dt=1991-02-13@16:00 dur=72:00 estart=1991-02-13@16:00 edur=72:00
       now=1991-02-14 dt=1991-02-14@00:00 dur=64:00 estart=1991-02-13@16:00 edur=72:00
       now=1991-02-15 dt=1991-02-15@00:00 dur=40:00 estart=1991-02-13@16:00 edur=72:00
       now=1991-02-16 dt=1991-02-16@00:00 dur=16:00 estart=1991-02-13@16:00 edur=72:00
       now=1991-02-17 dt=1991-02-13@16:00 dur=72:00 estart=-1 edur=-1

       As you see, the trigdatetime() and trigduration() functions return the start time  and  duration  of  the
       remaining  portion  of  a multi-day event, whereas trigeventstart and trigeventduration always return the
       original start and duration of the multi-day  event.   Note  also  that  the  return  value  for  expired
       reminders  is  not reliable; the fact that trigeventstart and trigeventduration return -1 in that case is
       an implementation artifact.

       SELF-OVERLAPPING EVENTS

       A multi-day event has the possibility of "overlapping itself".  When this  happens,  Remind  prefers  the
       later event (only one copy of an event is ever triggered for a given date.)  Consider this example:

          #!/bin/sh
          remind - '*5' 10 Feb 1991 <<'EOF'

          BANNER %
          REM MON at 0:00 DURATION 192:0 MSG [today()] [trigeventstart()] [trigduration()]%

          EOF

       The output is:

          1991-02-10 1991-02-04@00:00 48:00
          1991-02-11 1991-02-11@00:00 192:00
          1991-02-12 1991-02-11@00:00 168:00
          1991-02-13 1991-02-11@00:00 144:00
          1991-02-14 1991-02-11@00:00 120:00

       Although  the  event  from  1991-02-04  still  has  24  hours left on 1991-02-11, the fresh occurrence on
       1991-02-11 takes precedences and is the one that is triggered.

       I do not recommend constructing self-overlapping multi-day events.

EXPRESSION PASTING

       An extremely powerful feature of Remind is its macro capability, or "expression pasting."

       In almost any situation where Remind is not expecting an expression, you can "paste"  an  expression  in.
       To do this, surround the expression with square brackets.  For example:

            REM [mydate] MSG foo

       This evaluates the expression "mydate", where "mydate" is presumably some pre-computed variable, and then
       "pastes" the result into the command-line for the parser to process.

       If you want a literal "[" character for some reason, simply use "[[".  For example:

               REM MSG Here are [[square] brackets!

       A  formal  description  of  this  is:   When Remind encounters a "pasted-in" expression, it evaluates the
       expression, and coerces the result to a STRING.   It  then  substitutes  the  string  for  the  pasted-in
       expression,  and  continues  parsing.   Note,  however,  that  expressions  are  evaluated only once, not
       recursively.  Thus, writing:

            ["[a+b]"]

       causes Remind to read the token "[a+b]".  It does not interpret this as a pasted-in expression.  In fact,
       the only way to get a literal left-bracket into a reminder is to use ["["].

       You can use expression pasting almost anywhere.  However, there are a few exceptions:

       o      If Remind is expecting an expression, as in the SET command, or the IF  command,  you  should  not
              include square brackets.  For example, use:

                 SET a 4+5
       and not:
                 SET a [4+5]

       o      You  cannot use expression pasting for the first token on a line.  For example, the following will
              not work:

                 ["SET"] a 1

              This restriction is because Remind must be able to unambiguously determine the first  token  of  a
              line for the flow-control commands (to be discussed later.)

              In  fact,  if  Remind  cannot  determine  the  first  token on a line, it assumes that it is a REM
              command.  If expression-pasting is used, Remind assumes it is a REM command.  Thus, the  following
              three commands are equivalent:

                        REM 12 Nov 1993 AT 13:05 MSG BOO!
                        12 Nov 1993 AT 13:05 MSG BOO!
                        [12] ["Nov " + 1993] AT [12:05+60] MSG BOO!

       o      You  cannot  use  expression-pasting to determine the type (MSG, CAL, etc.) of a REM command.  You
              can paste expressions before and after the MSG, etc. keywords, but cannot do something like this:

                      REM ["12 Nov 1993 AT 13:05 " + "MSG" + " BOO!"]

              However, as an escape hatch, the sequence SPECIAL type means the same thing  as  just  type  where
              type is one of MSG, MSF, RUN, CAL, PS and PSFILE.  This lets you do something like this:

                      SET type "MSG"
                      REM 12 Nov 2024 SPECIAL [type] Hello

              You  can use this to control the types of your reminders based on variables you set, how Remind is
              invoked, etc.

       COMMON PITFALLS WITH EXPRESSION PASTING

       Remember that extra spaces are not inserted when an expression is pasted.  Thus, something like:

            REM[expr]MSG[expr]

       will probably fail.

       If you use an expression to calculate a delta or back, ensure that  the  result  is  a  positive  number.
       Something like:

            REM +[mydelta] Nov 12 1993 MSG foo

       will fail if mydelta happens to be negative.

FLOW CONTROL COMMANDS

       Remind has commands that control the flow of a reminder script.  Normally, reminder scripts are processed
       sequentially.   However,  IF  and  related  commands  allow  you to process files conditionally, and skip
       sections that you don't want interpreted.

       THE IF COMMAND

       The IF command has the following form:

            IF expr
                 t-command
                 t-command...
            ELSE
                 f-command
                 f-command...
            ENDIF

       Note that the commands are shown indented for clarity.  Also,  the  ELSE  portion  can  be  omitted.   IF
       commands  can be nested up to a small limit, probably around 8 or 16 levels of nesting, depending on your
       system.

       If the expr evaluates to a non-zero INT, a DATE that is not 1990-01-01, a  TIME  that  is  not  00:00,  a
       DATETIME  that is not 1990-01-01@00:00, or a non-null STRING, then the IF portion is considered true, and
       the t-commands are executed.  If expr evaluates to zero or null, then the f-commands (if the ELSE portion
       is present) are executed.

       Examples:

            IF defined("want_hols")
                 INCLUDE /usr/share/remind/holidays
            ENDIF

            IF today() > '1992/2/10'
                 set missed_ap "You missed it!"
            ELSE
                 set missed_ap "Still have time..."
            ENDIF

       THE IFTRIG COMMAND

       The IFTRIG command is similar to an IF command, except  that  it  computes  a  trigger  (as  in  the  REM
       command), and evaluates to true if a corresponding REM command would trigger.  Examples:

            IFTRIG 1 Nov
                 ; Executed on 1 Nov
            ELSE
                 ; Executed except on 1 Nov
            ENDIF

            IFTRIG 1 -1 OMIT Sat Sun +4
                 ; Executed on last working day of month,
                 ; and the 4 working days preceding it
            ELSE
                 ; Executed except on above days
            ENDIF

       Note  that  the  IFTRIG  command  computes  a  trigger  date,  which can be retrieved with the trigdate()
       function.  You can use all of the normal trigger components, such as UNTIL, delta,  etc.  in  the  IFTRIG
       command.   However,  you  cannot  use  a  type specifier such as CAL, MSG or SATISFY; attempting to do so
       yields a parse error.

USER-DEFINED FUNCTIONS

       In addition to the built-in functions, Remind allows you to define your own functions.  The FSET  command
       does this for you:

       FSET fname(args) expr

       Fname  is  the  name  of the function, and follows the convention for naming variables.  Args is a comma-
       separated list of arguments, and expr is an expression.  Args can be empty, in which case  you  define  a
       function taking no parameters.  Here are some examples:

            FSET double(x) 2*x
            FSET yeardiff(date1, date2) year(date1) - year(date2)
            FSET since(x) ord($Ty - x)

       The last function is useful in birthday reminders.  For example:

            REM 1 Nov +12 MSG Dean's [since(1984)] birthday is %b.

       Dean was born in 1984.  The above example, on 1 November 1992, would print:

            Dean's 8th birthday is today.

       Similarly, the function is useful in anniversary reminders.  For example:

               REM 4 June MSG [since(1989)] anniversary of the Tienanmen Square massacre

       Notes:

       o      If  you  access a variable in expr that is not in the list of arguments, the global value (if any)
              is used.

       o      Function and parameter names are significant to 64 characters.

       o      The value() function always accesses the global value of a variable, even if it has the same  name
              as an argument.  For example:

                        fset func(x) value("x")
                        set x 1
                        set y func(5)

              The above sequence sets y to 1, which is the global value of x.

       o      User-defined functions may call other functions, including other user-defined functions.  However,
              recursive calls are not allowed.

       o      User-defined functions are not syntax-checked when they are defined; parsing occurs only when they
              are called.

       o      If  a user-defined function has the same name as a built-in function, it is ignored and the built-
              in function is used.  To prevent conflicts with future versions of Remind (which may  define  more
              built-in functions), you may wish to name all user-defined functions beginning with an underscore.

       To  delete  a  user-defined  function,  use  FUNSET.   This  takes a space-separated list of user-defined
       functions to delete.  For example, after the command:

               FUNSET myfunc1 otherfunc thirdfunc

       it is guaranteed that no user-defined functions named myfunc1, otherfunc or thirdfunc will exist.  Remind
       does not issue an error if you try to FUNSET a nonexistent user-defined function; it simply does  nothing
       in that case.

PRECISE SCHEDULING

       The  WARN  keyword  allows  precise control over advance warning in a more flexible manner than the delta
       mechanism.  It should be followed by the name of a user-defined function, warn_function.

       If a warn_function is supplied, then it must take one argument of type INT.  Remind  ignores  any  delta,
       and instead calls warn_function successively with the arguments 1, 2, 3, ...

       Warn_function's return value n is interpreted as follows:

       o      If n is positive, then the reminder is triggered exactly n days before its trigger date.

       o      If n is negative, then it is triggered n days before its trigger date, not counting OMITted days.

       As  an  example,  suppose you wish to be warned of American Independence Day 5, 3, and 1 days in advance.
       You could use this:

            FSET _wfun(x) choose(x, 5, 3, 1, 0)
            REM 4 July WARN _wfun MSG American Independence Day is %b.

       NOTES

       1      If an error occurs during the evaluation of warn_function, then Remind stops calling it and simply
              issues the reminder on its trigger date.

       2      If the absolute-values of the return values of warn_function  are  not  monotonically  decreasing,
              Remind stops calling it and issues the reminder on its trigger date.

       3      Warn_function  should  (as  a matter of good style) return 0 as the final value in its sequence of
              return values.  However, a reminder will always be triggered on its trigger  date,  regardless  of
              what warn_function does.

       Similarly  to  WARN, the SCHED keyword allows precise control over the scheduling of timed reminders.  It
       should be followed by the name of a user-defined function, sched_function.

       If a scheduling function is supplied, then it must take one argument of type INT.  Rather than using  the
       AT  time,  time delta, and time repeat, Remind calls the scheduling function to determine when to trigger
       the reminder.  The first time the reminder is queued, the scheduling function is called with an  argument
       of  1.  Each time the reminder is triggered, it is re-scheduled by calling the scheduling function again.
       On each call, the argument is incremented by one.

       The return value of the scheduling function must be an INT or a TIME.  If the return  value  is  a  TIME,
       then the reminder is re-queued to trigger at that time.  If it is a positive integer n, then the reminder
       is  re-queued  to  trigger  at  the  previous  trigger time plus n minutes.  Finally, if it is a negative
       integer or zero, then the reminder is re-queued to trigger n minutes before the AT time.  Note that there
       must be an AT clause for the SCHED clause to do anything.

       Here's an example:

            FSET _sfun(x) choose(x, -60, 30, 15, 10, 3, 1, 1, 1, 1, 0)
            REM AT 13:00 SCHED _sfun MSG foo

       The reminder would first be triggered at 13:00-60 minutes, or at 12:00.  It would next  be  triggered  30
       minutes  later,  at  12:30.   Then, it would be triggered at 12:45, 12:55, 12:58, 12:59, 13:00, 13:01 and
       13:02.

       NOTES

       1      If an error occurs during the evaluation of sched_func, then Remind reverts to using the  AT  time
              and the delta and repeat values, and never calls sched_func again.

       2      If  processing  sched_func  yields  a  time earlier than the current system time, it is repeatedly
              called with increasing argument until it yields a value greater than or equal to the current time.
              However, if the sequence of values calculated during the repetition is  not  strictly  increasing,
              then Remind reverts to the default behaviour and never calls sched_func again.

       3      It  is  quite  possible  using  sched_func  to  keep triggering a reminder even after the AT-time.
              However, it is not possible to  reschedule  a  reminder  past  midnight  -  no  crossing  of  date
              boundaries  is  allowed.  Also, it is quite possible to not trigger a reminder on the AT time when
              you use a scheduling function.  However, if your scheduling function is terminated (for reasons  1
              and  2)  before  the  AT time of the reminder, it will be triggered at the AT time, because normal
              processing takes over.

       4      Your scheduling functions should (as a matter of good style) return 0 when no more  scheduling  is
              required.  See the example.

       5      All  scheduling  functions  are  evaluated  after  the  entire Remind script has been read in.  So
              whatever function definitions are in effect at the end of the script are used.

THE SATISFY CLAUSE

       The form of REM that uses SATISFY is as follows:

       REM trigger SATISFY expr

       The way this works is as follows:  Remind first calculates a trigger date, in the normal fashion.   Next,
       it  sets  trigdate()  to  the calculated trigger date.  It then evaluates expr.  If the result is not the
       null string or zero, processing ends.  Otherwise, Remind computes the next  trigger  date,  and  re-tests
       expr.   This  iteration  continues  until  expr evaluates to non-zero or non-null, or until the iteration
       limit specified with the -x command-line option is reached.

       If expr is not satisfied, then trigvalid() is set to 0 and the error message "Can't compute  trigger"  is
       issued.  Otherwise, trigvalid() is set to 1.

       This  is  really  useful  only if expr involves a call to the trigdate() or related functions; otherwise,
       expr will not change as Remind iterates.

       An example of the usefulness of SATISFY:  Suppose you wish to be warned of every Friday the  13th.   Your
       first attempt may be:

            # WRONG!
            REM Fri 13 +2 MSG Friday the 13th is %b.

       But this won't work.  This reminder triggers on the first Friday on or after the 13th of each month.  The
       way to do it is with a more complicated sequence:

            REM 13 SATISFY wkdaynum(trigdate()) == 5
            IF trigvalid()
                 REM [trigdate()] +2 MSG \
                 Friday the 13th is %b.
            ENDIF

       You can write the REM statement a little more concisely:

            REM 13 SATISFY $Tw == 5

       Let's  see how this works.  The SATISFY clause iterates through all the 13ths of successive months, until
       a trigger date is found whose day-of-week is Friday (== 5).  If a  valid  date  was  found,  we  use  the
       calculated trigger date to set up the next reminder.

       We could also have written:

            REM Fri SATISFY day(trigdate()) == 13

       but this would result in more iterations, since "Fridays" occur more often than "13ths of the month."

       Here  is  another  example:  Suppose  you want to be reminded of something on the 15th of January, April,
       July, and October.  You could make four separate reminders, or you could use:

               REM 15 SATISFY [isany($Tm, 1, 4, 7, 10)] MSG 15th Reminder!

       This technique of using one REM command to calculate a trigger date to be  used  by  another  command  is
       quite  powerful.   For  example,  suppose  you  wanted  to  OMIT Labour day, which is the first Monday in
       September.  You could use:

            # Note: SATISFY 1 is an idiom for "do nothing"
            REM Mon 1 Sept SATISFY 1
            OMIT [trigdate()]

       CAVEAT: This only omits the next Labour Day, not all Labour Days in the future.  This could cause strange
       results, as the OMIT context can change depending on the current date.   For  example,  if  you  use  the
       following command after the above commands:

            REM Mon AFTER msg hello

       the result will not be as you expect.  Consider producing a calendar for September, 1992.  Labour Day was
       on Monday, 7 September, 1992.  However, when Remind gets around to calculating the trigger for Tuesday, 8
       September,  1992,  the OMIT command will now be omitting Labour Day for 1993, and the "Mon AFTER" command
       will not be triggered.  (But see the description of  SCANFROM  in  the  section  "DETAILS  ABOUT  TRIGGER
       COMPUTATION.")

       It  is  probably  best  to  stay away from computing OMIT trigger dates unless you keep these pitfalls in
       mind.

       For versions of Remind starting from 03.00.07, you can include a MSG,  RUN,  etc.  clause  in  a  SATISFY
       clause as follows:

            REM trigger_stuff SATISFY [expr] MSG body

       Note  that  for this case only, the expr after SATISFY must be enclosed in square brackets.  It must come
       after all the other components of the trigger, and immediately before the MSG,  RUN,  etc.  keyword.   If
       expr cannot be satisfied, then the reminder is not triggered.

       Thus, the "Friday the 13th" example can be expressed more compactly as:

            REM 13 +2 SATISFY [$Tw == 5] MSG Friday the 13th is %b.

       And you can trigger a reminder on Mondays, Wednesdays and Thursdays occurring on odd-numbered days of the
       month with the following:

            REM Mon Wed Thu SATISFY [$Td %2 ] MSG Here it is!!!

       Note  that  SATISFY  and  OMITFUNC can often be used to solve the same problem, though in different ways.
       Sometimes a SATISFY is cleaner and sometimes an OMITFUNC; experiment and use whichever seems clearer.

POSSIBLY-UNCOMPUTABLE TRIGGERS

       Occasionally, you may wish to suppress the "Can't compute trigger" warnings for  reminders  for  which  a
       trigger  date  cannot  be computed.  For example, the following reminder is triggered on a Monday that is
       not a holiday if the following Tuesday is a holiday:

               REM Mon SKIP SATISFY [isomitted($T+1)] MSG Work between holidays

       However, if there are no Mondays after today's date that satisfy the condition,  Remind  will  print  the
       "Can't compute trigger" error.  To suppress this, use the MAYBE-UNCOMPUTABLE keyword:

               REM MAYBE-UNCOMPUTABLE Mon SKIP SATISFY [isomitted($T+1)] MSG Work between holidays

       It's almost never appropriate to use MAYBE-UNCOMPUTABLE, but it is provided for those rare occasions when
       it  makes  sense.   If  you  use  MAYBE-UNCOMPUTABLE  inside  the evaltrig() function, then untriggerable
       triggers return -1.  For example:

               SET a evaltrig("MAYBE-UNCOMPUTABLE Mon SKIP OMIT Mon")

       will set a to -1.

DEBUGGING REMINDER SCRIPTS

       Although the command-line -d option is useful for debugging, it is often overkill.  For example,  if  you
       turn  on  the  -dx  option for a reminder file with many complex expressions, you'll get a huge amount of
       output.  The DEBUG command allows you to control the debugging flags under program control.   The  format
       is:

       DEBUG [+flagson] [-flagsoff]

       Flagson  and  flagsoff  consist  of  strings of the characters "extvlfs" that correspond to the debugging
       options discussed in the command-line options section.  If preceded with a "+", the  corresponding  group
       of  debugging options is switched on.  Otherwise, they are switched off.  For example, you could use this
       sequence to debug a complicated expression:

            DEBUG +x
            set a very_complex_expression(many_args)
            DEBUG -x

       THE DUMPVARS COMMAND

       The command DUMPVARS displays the values of variables in memory.  Its format is:

       DUMPVARS [var...]

       If you supply a space-separated list of variable names, the corresponding variables  are  displayed.   If
       you  do  not  supply  a  list of variables, then all variables in memory are displayed.  To dump a system
       variable, put its name in the list of variables to dump.  If you put a lone dollar sign in  the  list  of
       variables to dump, then all system variables will be dumped.

       THE ERRMSG COMMAND

       The ERRMSG command has the following format:

       ERRMSG body

       The body is passed through the substitution filter (with an implicit trigger date of today()) and printed
       to the error output stream.  Example:

            IF !defined("critical_var")
                 ERRMSG You must supply a value for "critical_var"
                 EXIT
            ENDIF

       THE EXIT COMMAND

       The  above example also shows the use of the EXIT command.  This causes an unconditional exit from script
       processing.  Any queued timed reminders are discarded.  If you are in  calendar  mode  (described  next),
       then the calendar processing is aborted.

       If you supply an INT-type expression after the EXIT command, it is returned to the calling program as the
       exit status.  Otherwise, an exit status of 99 is returned.

       THE FLUSH COMMAND

       This  command  simply  consists  of the word FLUSH on a line by itself.  The command flushes the standard
       output and standard error streams used by Remind.  This is not terribly useful to most people, but may be
       useful if you run Remind as a subprocess of another program, and want to use pipes for communication.

CALENDAR MODE

       If you supply the -c, -s or -p command-line option, then Remind runs in "calendar mode."  In  this  mode,
       Remind  interprets the script repeatedly, performing one iteration through the whole file for each day in
       the calendar.  Reminders that trigger are saved in internal buffers, and then inserted into the  calendar
       in the appropriate places.

       If you also supply the -a option, then Remind will not include timed reminders in the calendar.

       The  -p option is used in conjunction with the Rem2PS program to produce a calendar in PostScript format.
       For example, the following command will send PostScript code to standard output:

            remind -p .reminders | rem2ps

       You can print a PostScript calendar by piping this to the lpr command.

       If you have a reminder script called ".reminders", and you execute this command:

            remind -c .reminders jan 1993

       then Remind executes the script 31 times, once for each day  in  January.   Each  time  it  executes  the
       script, it increments the value of today().  Any reminders whose trigger date matches today() are entered
       into the calendar.

       MSG  and  CAL-type  reminders,  by  default, have their entire body inserted into the calendar.  RUN-type
       reminders are not normally inserted into the calendar.  However, if you enclose a portion of the body  in
       the %"...%" sequence, only that portion is inserted.  For example, consider the following:

            REM 6 Jan MSG %"Dianne's birthday%" is %b

       In  the  normal  mode,  Remind  would  print  "Dianne's birthday is today" on 6 January.  However, in the
       calendar mode, only the text "Dianne's birthday" is inserted into the box for 6 January.

       If you explicitly use the %"...%" sequence in a RUN-type reminder, then the text between  the  delimiters
       is  inserted  into  the  calendar.   If  you use the sequence %"%" in a MSG or CAL-type reminder, then no
       calendar entry is produced for that reminder.

       PRESERVING VARIABLES

       Because Remind iterates through the script for each day in the calendar,  slow  operations  may  severely
       reduce the speed of producing a calendar.

       For example, suppose you set the variables "me" and "hostname" as follows:

            SET me shell("whoami")
            SET hostname shell("hostname")

       Normally, Remind clears all variables between iterations in calendar mode.  However, if certain variables
       are  slow  to  compute,  and will not change between iterations, you can "preserve" their values with the
       PRESERVE command.  Also, since function definitions are preserved between calendar iterations,  there  is
       no need to redefine them on each iteration.  Thus, you could use the following sequence:

            IF ! defined("initialized")
                 set initialized 1
                 set me shell("whoami")
                 set hostname shell("hostname")
                 fset func(x) complex_expr
                 preserve initialized me hostname
            ENDIF

       The  operation  is  as follows:  On the first iteration through the script, "initialized" is not defined.
       Thus, the commands between IF and ENDIF are executed.  The PRESERVE command ensures that  the  values  of
       initialized,  me  and  hostname  are  preserved  for  subsequent  iterations.  On the next iteration, the
       commands are skipped, since initialized has remained defined.  Thus, time-consuming  operations  that  do
       not depend on the value of today() are done only once.

       Most  system  variables  (those  whose names start with '$') are automatically preserved between calendar
       iterations.

       Note that for efficiency, Remind caches the reminder script (and  any  INCLUDEd  files)  in  memory  when
       producing a calendar.

       Timed  reminders  are sorted and placed into the calendar in time order.  These are followed by non-timed
       reminders.  Remind automatically places the time of timed reminders in the calendar according to  the  -b
       command-line  option.   Reminders  in calendar mode are sorted as if the -g option had been used; you can
       change the sort order in calendar mode by explicitly using the -g option to  specify  a  different  order
       from the default.

       REPEATED EXECUTION

       If  you  supply  a repeat parameter on the command line, and do not use the -c, -p, or -s options, Remind
       operates in a similar manner to calendar mode.  It repeatedly executes the reminder script,  incrementing
       today()  with  each iteration.  The same rules about preserving variables and function definitions apply.
       Note that using repeat on the command line also enables the -q option and disables any -z option.  As  an
       example, if you want to see how Remind will behave for the next week, you can type:

            remind .reminders '*7'

       If you want to print the dates of the next 1000 days, use:

            (echo 'banner %'; echo 'msg [today()]%') | remind - '*1000'

INITIALIZING VARIABLES ON THE COMMAND LINE

       The  -i  option  is  used  to initialize variables on the Remind command line.  The format is -ivar=expr,
       where expr is any valid expression.  Note that you may have to use quotes or escapes to prevent the shell
       from interpreting special characters in expr.  You can have as many -i options as you want on the command
       line, and they are processed in order.  Thus, if a variable is defined  in  one  -i  option,  it  can  be
       referred to by subsequent -i options.

       Note  that  if  you  supply  a  date  on  the  command line, it is not parsed until all options have been
       processed.  Thus, if you use today() in any of the -i expressions, it  will  return  the  same  value  as
       realtoday() and not the date supplied on the command line.

       Any variables defined on the command line are preserved as with the PRESERVE command.

       You  should  not  have  any  spaces between the -i option and the equal sign; otherwise, strange variable
       names are created that can only be accessed with the value() or defined() functions.

       You can also define a function on the command line by using:

       -ifunc(args)=definition

       Be sure to protect special characters from shell interpretation.

MORE ABOUT POSTSCRIPT

       The PS and PSFILE reminders pass PostScript code directly to the printer.  They differ in  that  the  PS-
       type  reminder  passes  its  body directly to the PostScript output (after processing by the substitution
       filter) while the PSFILE-type's body should simply consist of a filename.  The Rem2PS program  will  open
       the file named in the PSFILE-type reminder, and include its contents in the PostScript output.

       The  PostScript-type reminders for a particular day are included in the PostScript output in sorted order
       of priority.  Note that the order of PostScript commands has a major impact  on  the  appearance  of  the
       calendars.   For  example,  PostScript  code  to shade a calendar box will obliterate code to draw a moon
       symbol if the moon symbol code is placed in the calendar first.  For this reason, you should not  provide
       PS  or PSFILE-type reminders with priorities; instead, you should ensure that they appear in the reminder
       script in the correct order.  PostScript code should draw objects working  from  the  background  to  the
       foreground,  so  that  foreground  objects  properly  overlay  background  ones.  If you prioritize these
       reminders and run the script using descending sort order for priorities, the PostScript output  will  not
       work.

       All of the PostScript code for a particular date is enclosed in a save-restore pair.  However, if several
       PostScript-type reminders are triggered for a single day, each section of PostScript is not enclosed in a
       save-restore pair - instead, the entire body of included PostScript is enclosed.

       PostScript-type  reminders  are  executed  by the PostScript printer before any regular calendar entries.
       Thus, regular calendar entries will overlay the PostScript-type reminders, allowing you to create  shaded
       or graphical backgrounds for particular days.

       Before  executing  your  PostScript code, the origin of the PostScript coordinate system is positioned to
       the bottom left-hand corner of the "box" in the calendar representing today().  This location is  exactly
       in  the  middle of the intersection of the bottom and left black lines delineating the box - you may have
       to account for the thickness of these lines when calculating positions.

       Several PostScript variables are available to the PostScript code you  supply.   All  distance  and  size
       variables are in PostScript units (1/72 inch.)  The variables are:

       LineWidth
              The width of the black grid lines making up the calendar.

       Border The  border  between  the  center  of the grid lines and the space used to print calendar entries.
              This border is normally blank space.

       BoxWidth and BoxHeight
              The width and height of the calendar box, from center-to-center of the black gridlines.

       InBoxHeight
              The height from the center of the bottom black gridline to the top of the regular  calendar  entry
              area.  The space from here to the top of the box is used only to draw the day number.

       /DayFont, /EntryFont, /SmallFont, /TitleFont and /HeadFont
              The  fonts  used  to draw the day numbers, the calendar entries, the small calendars, the calendar
              title (month, year) and the day-of-the-week headings, respectively.

       DaySize, EntrySize, TitleSize and HeadSize
              The sizes of the above fonts.  (The size of the small calendar font is  not  defined  here.)   For
              example,  if  you  wanted to print the Hebrew date next to the regular day number in the calendar,
              use:

            REM PS Border BoxHeight Border sub DaySize sub moveto \
               /DayFont findfont DaySize scalefont setfont \
               ([hebday(today())] [hebmon(today())]) show

              Note how /DayFont and DaySize are used.

       Note that if you supply PostScript code, it is possible to produce invalid PostScript files.  Always test
       your PostScript thoroughly with a PostScript viewer before sending it to the printer.  You should not use
       any document structuring comments in your PostScript code.

DAEMON MODE

       If you use the -z command-line option, Remind runs in "daemon mode".  In this mode, no "normal" reminders
       are issued.  Instead, only timed reminders are collected and queued, and are then  issued  whenever  they
       reach their trigger time.

       In addition, Remind wakes up every few minutes to check the modification date on the reminder script (the
       filename  supplied  on  the command line.)  If Remind detects that the script has changed, it re-executes
       itself in daemon mode, and interprets the changed script.   If  Remind  was  compiled  with  support  for
       inotify(7),  then  if  the  command-line  reminder  script is really a directory, Remind also re-executes
       itself if any of the files in the directory is changed.

       In daemon mode, Remind also re-reads the remind script when it detects that the system date has changed.

       In daemon mode, Remind acts as if the -f option  had  been  used,  so  to  run  in  daemon  mode  in  the
       background, use:

            remind -z .reminders &

       If  you  use  sh or bash, you may have to use the "nohup" command to ensure that the daemon is not killed
       when you log out.

PURGE MODE

       If you supply the -j command-line option, Remind runs in purge mode.  In this mode,  it  tries  to  purge
       expired reminders from your reminder files.

       In  purge  mode,  Remind  reads  your  reminder file and creates a new file by appending ".purged" to the
       original file name.  Note that Remind never edits your original file; it always  creates  a  new  .purged
       file.

       If you invoke Remind against a directory instead of a file, then a .purged file is created for each *.rem
       file in the directory.

       Normally,  Remind  does  not  create  .purged files for INCLUDed files.  However, if you supply a numeric
       argument after -j, then Remind will create .purged  files  for  the  specified  level  of  INCLUDE.   For
       example,  if you invoke Remind with the argument -j2, then .purged files will be created for the file (or
       directory) specified on the command line, any files included by them, and any  files  included  by  those
       files.  However, .purged files will not be created for third-or-higher level INCLUDE files.

       Determining  which  reminders  have  expired  is  extremely tricky.  Remind does its best, but you should
       always compare the .purged file to the original file and hand-merge the changes back in.

       Remind annotates the .purged file as follows:

       An expired reminder is prefixed with:  #!P: Expired:

       In situations where Remind cannot reliably  determine  that  something  was  expired,  you  may  see  the
       following comments inserted before the problematic line:

          #!P: Cannot purge SATISFY-type reminders

          #!P: The next IF evaluated false...
          #!P: REM statements in IF block not checked for purging.

          #!P: The previous IF evaluated true.
          #!P: REM statements in ELSE block not checked for purging

          #!P: The next IFTRIG did not trigger.
          #!P: REM statements in IFTRIG block not checked for purging.

          #!P: Next line has expired, but contains expression...  please verify

          #!P: Next line may have expired, but contains non-constant expression

          #!P! Could not parse next line: Some-Error-Message-Here

       Remind  always annotates .purged files with lines beginning with "#!P".  If such lines are encountered in
       the original file, they are not copied to the .purged file.

SORTING REMINDERS

       The -g option causes Remind to sort reminders by trigger date, time and  priority  before  issuing  them.
       Note  that  reminders  are still calculated in the order encountered in the script.  However, rather than
       being issued immediately, they are saved in an internal buffer.  When Remind has finished processing  the
       script,  it  issues  the  saved  reminders  in sorted order.  The -g option can be followed by up to four
       characters that must all be "a" or "d".  The first character specifies the sort  order  by  trigger  date
       (ascending  or  descending),  the second specifies the sort order by trigger time and the third specifies
       the sort order by priority.  If the fourth character is "d", the  untimed  reminders  are  sorted  before
       timed  reminders.   The  default  is  to sort all fields in ascending order and to sort untimed reminders
       after timed reminders.

       In ascending order, reminders are issued with the most imminent first.  Descending order is the  reverse.
       Reminders  are always sorted by trigger date, and reminders with the same trigger date are then sorted by
       trigger time.  If two reminders have the same date and time, then the priority is  used  to  break  ties.
       Reminders with the same date, time and priority are issued in the order they were encountered.

       You  can  define  a  user-defined  function called SORTBANNER that takes one DATE-type argument.  In sort
       mode, the following sequence happens:

       If Remind notices that the next reminder to issue has a different trigger date from the previous one  (or
       if  it  is  the first one to be issued), then SORTBANNER is called with the trigger date as its argument.
       The result is coerced to a string, and passed  through  the  substitution  filter  with  the  appropriate
       trigger date.  The result is then displayed.

       Here's an example - consider the following fragment:

            # Switch off the normal banner
            BANNER %
            REM 11 March 1993 ++1 MSG Not so important
            REM 17 March 1993 ++7 MSG Way in the future
            REM 10 March 1993 MSG Important Reminder
            REM 11 March 1993 ++1 MSG Not so important - B
            FSET sortbanner(x) iif(x == today(), \
                 "***** THINGS TO DO TODAY *****", \
                 "----- Things to do %b -----")

       Running this with the -gaa option on 10 March 1993 produces the following output:

            ***** THINGS TO DO TODAY *****

            Important Reminder

            ----- Things to do tomorrow -----

            Not so important

            Not so important - B

            ----- Things to do in 7 days' time -----

            Way in the future

       You  can use the args() built-in function to determine whether or not SORTBANNER has been defined.  (This
       could be used, for example, to provide a default definition for SORTBANNER in a system-wide file included
       at the end of the user's file.)  Here's an example:

            # Create a default sortbanner function if it hasn't already
            # been defined
            if args("sortbanner") != 1
                 fset sortbanner(x) "--- Things to do %b ---"
            endif

MSGPREFIX() AND MSGSUFFIX()

       You can define two functions in your script called msgprefix() and msgsuffix().  They should each  accept
       one argument, a number from 0 to 9999.

       In  normal  mode,  for  MSG- and MSF-type reminders, the following sequence occurs when Remind triggers a
       reminder:

       o      If msgprefix() is defined, it is evaluated with the priority of the reminder as its argument.  The
              result is printed.  It is not passed through the substitution filter.

       o      The body of the reminder is printed.

       o      If msgsuffix() is defined, it is evaluated with the priority of the reminder as its argument.  The
              result is printed.  It is not passed through the substitution filter.

       Here's an example:  The following definition causes priority-0 reminders to be preceded by "URGENT",  and
       priority-6000 reminders to be preceded by "(not important)".

            fset msgprefix(x) iif(x==0, "URGENT: ", \
                 x==6000, "(not important) ", "")

       In  Calendar  Mode  (with the -c, -s or -p options), an analogous pair of functions named calprefix() and
       calsuffix() can be defined.  They work with all reminders that produce an entry in  the  calendar  (i.e.,
       CAL- and possibly RUN-type reminders as well as MSG-type reminders.)

       NOTES

       Normally, the body of a reminder is followed by a carriage return.  Thus, the results of msgsuffix() will
       appear  on  the  next line.  If you don't want this, end the body of the reminder with a percentage sign,
       "%".  If you want a space between your reminders, simply include a carriage return (char(13)) as part  of
       the msgsuffix() return value.

       If  Remind  has problems evaluating msgprefix(), msgsuffix() or sortbanner(), you will see a lot of error
       messages.  For an example of this, define the following:

            fset msgprefix(x) x/0

COMPILE-TIME SUPPORT FOR OTHER LANGUAGES

       Your version of Remind may have been compiled to support a language other than English.  This support may
       or may not be complete - for example, all error and usage messages may still be in English.  However,  at
       a  minimum,  non-English  versions  of  Remind  will  output names of months and weekdays in the selected
       language.  Also, the substitution mechanism will substitute constructs suitable for the selected language
       rather than for English.

       Note that a non-English version of Remind will accept only English names of  weekdays  and  months  in  a
       reminder script.

RUN-TIME SUPPORT FOR OTHER LANGUAGES

       Remind  has  run-time  support  for other languages, and it is expected that compile-time support will be
       deprecated in favour of run-time support.

       A number of system variables let  you  translate  various  phrases  to  other  languages.   These  system
       variables are:

       $Monday, $Tuesday, $Wednesday, $Thursday, $Friday, $Saturday, $Sunday
              Set  each  of these system variables to a string representing the corresponding day's name in your
              language.  Strings must be valid UTF-8 strings.

       $January, $February, $March, $April, $May, $June, $July, $August, $September, $October, $November,
       $December
              Set each of these system variables to a string representing the corresponding month's name in your
              language.  Strings must be valid UTF-8 strings.

       $Ago, $Am, $And, $At, $Hour, $Is, $Minute, $Now, $On, $Pm, $Was
              Set each of these system variables to the translation of the corresponding English word into  your
              language.   Note  that  $Am  and  $Pm  should  be  the  translations of "AM" and "PM" (morning and
              afternoon time indicators) respectively.

       $Hplu, $Mplu
              Set these to the suffix to add to the word for "hour"  and  "minute"  to  make  them  plural.   In
              English, both would be set to "s".

       $Fromnow
              Set this to the translation of the English phrase "from now"

       Note  that  if  you  set any of the language-related system variables, they should be set in a section of
       your script that always is evaluated.  If you set them inside an IF statement, for example,  results  are
       unpredictable.

       Note  also  that  the Rem2PS back-end does not support the full range of UTF-8 characters.  The TkRemind,
       rem2html and rem2pdf back-ends all do support the full UTF-8 range.

RUN-TIME MODIFICATION OF THE SUBSTITUTION FILTER

       The system variables mentioned in the previous section are not typically sufficient to properly translate
       Remind's output to another language.  Some languages have complicated rules for AM vs PM times and others
       have complex rules for making words plural.  Remind therefore allows you to define a number of  functions
       that modify the behavior of the substitution filter at run-time.  The functions are:

       subst_ampm(h)
              This  function is passed a single integer, namely an hour from 0 to 23.  It should return a string
              that indicates "AM" or "PM" or even finer gradations in some languages.

       subst_ordinal(d)
              This function is passed a single integer, namely a day of the month  from  1  to  31.   It  should
              return a string that is suffixed to the day number to turn it into an ordinal number.  In English,
              for example, the function might return "st", "nd", "rd" or "th", depending on d.

       subst_N(alt, date, time)
              This  is  actually a family of functions, where N is a letter or number.  This function completely
              overrides the substitution sequence "%N".  The three arguments are an integer alt which,  if  non-
              zero, indicates that the alternate-mode substitution sequence "%*N" was encountered; date which is
              the trigger date of the reminder and time which is the trigger time.

       subst_Nx(alt, date, time)
              Again,  this  is  a  family  of  functions.  It is similar to the subst_N family except it is only
              called if date is two or more days away from today().   This  is  useful  if  you  don't  want  to
              override the "today" or "tomorrow" output for most substitution sequences.

       Here's  an  example  of how you might customize your substitution filter.  Suppose you want to change the
       "%b" sequence to substitute "the day after tomorrow" for an event two days from now.  You could do this:

           FSET subst_bx(a,d,t) iif(d==today()+2, "the day after tomorrow", \
                                    "in " + (d-today()) + " days' time")
           REM [today()+3] ++3 MSG Event 1 is %b%
           REM [today()+2] ++3 MSG Event 2 is %b%
           REM [today()+1] ++3 MSG Event 3 is %b%
           REM [today()]   ++3 MSG Event 4 is %b%

       The output of this script is:

           Event 1 is in 3 days' time
           Event 2 is the day after tomorrow
           Event 3 is tomorrow
           Event 4 is today

       Note how Event 2's wording was changed from the normal  "in  2  days'  time",  and  note  also  that  the
       "tomorrow"  and  "today" events used the normal substitution---subst_bx is not called for trigger days of
       today or tomorrow.

       As a special case, if a  subst_Nx  or  subst_N  function  returns  the  integer  zero,  then  the  normal
       substitution mechanism is used.  Therefore, the previous example could have been written more simply as:

           FSET subst_bx(a,d,t) iif(d==today()+2, "the day after tomorrow", 0)

       You  can  define  your  own  substitution  sequences in addition to the built-in ones as follows:  If you
       define a function named subst_name(alt, date, time), then the sequence %{name} calls  the  function  with
       alt  set  to  0  and  date  and time to the trigger date and time, respectively.  The %{name} sequence is
       replaced with whatever the function returns.  The sequence %*{name} is similar, but  calls  the  function
       with alt set to 1.

       If  you  use  a  %{name}  sequence  and  the function subst_name is not defined or returns an error, then
       %{name} is replaced with the empty string.

LANGUAGE PACKS

       Remind  ships  with  a  number  of  language  packs,  which  are  simply  reminder  scripts  located   in
       [$SysInclude]/lang.  The currently-shipping language packs are:

       da.rem  (Danish),  de.rem  (German),  es.rem  (Spanish),  fr.rem  (French),  is.rem  (Icelandic),  it.rem
       (Italian),  nl.rem  (Dutch),  no.rem  (Norwegian),  pl.rem  (Polish),  pt.rem  (Portuguese)  and   ro.rem
       (Romanian).

       To use a language pack (in this example, de.rem), simply place this at the top of your reminders file:

           INCLUDE [$SysInclude]/lang/de.rem

       If you want Remind to try to find the language pack appropriate for your locale settings, use:

           INCLUDE [$SysInclude]/lang/auto.rem

       You are encouraged to study the language packs to see how to translate Remind into additional languages.

THE HEBREW CALENDAR

       Remind  has  support  for the Hebrew calendar, which is a luni-solar calendar.  This allows you to create
       reminders for Jewish holidays, jahrzeits (anniversaries of deaths) and smachot (joyous occasions.)

       THE HEBREW YEAR

       The Hebrew year has 12 months, alternately 30 and 29  days  long.   The  months  are:  Tishrey,  Heshvan,
       Kislev,  Tevet, Shvat, Adar, Nisan, Iyar, Sivan, Tamuz, Av and Elul.  In Biblical times, the year started
       in Nisan, but Rosh Hashana (Jewish New Year) is now celebrated on the 1st and 2nd of Tishrey.

       In a cycle of 19 years, there are 7 leap years, being years 3, 6, 8, 11, 14, 17 and 19 of the cycle.   In
       a leap year, an extra month of 30 days is added before Adar.  The two Adars are called Adar A and Adar B.

       For  certain  religious  reasons,  the year cannot start on a Sunday, Wednesday or Friday.  To adjust for
       this, a day is taken off Kislev or added to Heshvan.  Thus, a regular year can have from 353 to 355 days,
       and a leap year from 383 to 385.

       When Kislev or Heshvan is short, it is called chaser, or lacking.  When it is long, it is called  shalem,
       or full.

       The  Jewish date changes at sunset.  However, Remind will change the date at midnight, not sunset.  So in
       the period between sunset and midnight, Remind will be a day earlier than the  true  Jewish  date.   This
       should not be much of a problem in practice.

       The  computations for the Jewish calendar were based on the program "hdate" written by Amos Shapir of the
       Hebrew University of Jerusalem, Israel.  He also supplied the preceding explanation of the calendar.

       HEBREW DATE FUNCTIONS

       hebday(d_date)
              Returns the day of the Hebrew month corresponding to the date parameter.  For  example,  12  April
              1993 corresponds to 21 Nisan 5753.  Thus, hebday('1993/04/12') returns 21.

       hebmon(d_date)
              Returns  the  name  of  the Hebrew month corresponding to date.  For example, hebmon('1993/04/12')
              returns "Nisan".

       hebyear(d_date)
              Returns the Hebrew year corresponding to date.  For example, hebyear('1993/04/12') returns 5753.

       hebdate(i_day, s_hebmon [,id_yrstart [,i_jahr [,i_aflag]]])
              The hebdate() function is the most complex of the Hebrew support functions.  It can take from 2 to
              5 arguments.  It returns a DATE corresponding to the Hebrew date.

              The day parameter can range from 1 to 30, and specifies the day of the Hebrew month.   The  hebmon
              parameter  is  a  string  that  must name one of the Hebrew months specified above.  Note that the
              month must be spelled out in full, and use the English transliteration shown previously.  You  can
              also specify "Adar A" and "Adar B."  Month names are not case-sensitive.

              The  yrstart  parameter can either be a DATE or an INT.  If it is a DATE, then the hebdate() scans
              for the first Hebrew date on or after that date.  For example:

                        hebdate(15, "Nisan", '1990/01/01')

              returns 1990/03/30, because that is the first occurrence of 15 Nisan on or after 1 January 1990.

              If yrstart is an INT, it is interpreted as a Hebrew year.  Thus:

                        hebdate(22, "Kislev", 5756)

              returns 1995/12/15, because that date corresponds to 22 Kislev,  5756.   Note  that  none  of  the
              Hebrew date functions will work with dates outside Remind's normal range for dates.

              If yrstart is not supplied, it defaults to today().

              The jahr modifies the behaviour of hebdate() as follows:

              If  jahr  is  0  (the  default),  then hebdate() keeps scanning until it finds a date that exactly
              satisfies the other parameters.  For example:

                        hebdate(30, "Adar A", 1993/01/01)

              returns 1995/03/02, corresponding to 30 Adar A, 5755, because that is the next  occurrence  of  30
              Adar  A  after 1 January, 1993.  This behaviour is appropriate for Purim Katan, which only appears
              in leap years.

              If jahr is 1, then the date is modified as follows:

              o      30 Heshvan is converted to 1 Kislev in years when Heshvan is chaser

              o      30 Kislev is converted to 1 Tevet in years when Kislev is chaser

              o      30 Adar A is converted to 1 Nisan in non-leapyears

              o      Other dates in Adar A are moved to the corresponding day in Adar in non-leapyears

              This behaviour is appropriate for  smachot  (joyous  occasions)  and  for  some  jahrzeits  -  see
              "JAHRZEITS."

              if jahr is 2, then the date is modified as follows:

              o      30  Kislev  and  30 Heshvan are converted to 29 Kislev and 29 Heshvan, respectively, if the
                     month is chaser

              o      30 Adar A is converted to 30 Shvat in non-leapyears

              o      Other dates in Adar A are moved to the corresponding day in Adar in non-leapyears

              if jahr is not 0, 1, or 2, it is interpreted as a Hebrew year, and the behaviour is calculated  as
              described in the next section, "JAHRZEITS."

              The  aflag  parameter  modifies the behaviour of the function for dates in Adar during leap years.
              The aflag is only used if yrstart is a DATE type.

              The aflag only affects date calculations if hebmon is specified as "Adar".   In  leap  years,  the
              following algorithm is followed:

              o      If aflag is 0, then the date is triggered in Adar B.  This is the default.

              o      If aflag is 1, then the date is triggered in Adar A.  This may be appropriate for jahrzeits
                     in the Ashkenazi tradition; consult a rabbi.

              o      If  aflag  is 2, then the date is triggered in both Adar A and Adar B of a leap year.  Some
                     Ashkenazim perform jahrzeit in both Adar A and Adar B.

       JAHRZEITS

       A jahrzeit is a yearly commemoration of someone's death.  It normally takes place on the  anniversary  of
       the death, but may be delayed if burial is delayed - consult a rabbi for more information.

       In  addition,  because  some months change length, it is not obvious which day the anniversary of a death
       is.  The following rules are used:

       o      If the death occurred on 30 Heshvan, and Heshvan in the year after the death is chaser,  then  the
              jahrzeit  is  observed  on 29 Heshvan in years when Heshvan is chaser.  Otherwise, the jahrzeit is
              observed on 1 Kislev when Heshvan is chaser.

       o      If the death occurred on 30 Kislev, and Kislev in the year after the death  is  chaser,  then  the
              jahrzeit  is  observed  on  29  Kislev in years when Kislev is chaser.  Otherwise, the jahrzeit is
              observed on 1 Tevet when Kislev is chaser.

       o      If the death occurred on 1-29 Adar A, it is observed on 1-29 Adar in non-leapyears.

       o      If the death occurred on 30 Adar A, it is observed on 30 Shvat in a non-leapyear.

       Specifying a Hebrew year for the jahr parameter causes the correct behaviour to be selected for  a  death
       in that year.  You may also have to specify aflag, depending on your tradition.

       The  jahrzeit information was supplied by Frank Yellin, who quoted "The Comprehensive Hebrew Calendar" by
       Arthur Spier, and "Calendrical Calculations" by E. M. Reingold and Nachum Dershowitz.

OUT-OF-BAND REMINDERS

       The SPECIAL keyword is used to transmit "out-of-band" information to Remind backends, such as tkremind or
       Rem2PS.  They are used only when piping data from a remind -p line.  (Note that the COLOR special  is  an
       exception; it downgrades to the equivalent of MSG in Remind's normal mode of operation.)

       The  various  SPECIALs  recognized are particular for each backend; however, there are four SPECIALs that
       all backends should attempt to support.  They are currently supported by Rem2PS, tkremind and rem2html.

       The SHADE special replaces the psshade() function.  Use it like this:

            REM Sat Sun SPECIAL SHADE 128
            REM Mon SPECIAL SHADE 255 0 0

       The SHADE keyword is followed by either one or three numbers, from 0 to 255.  If one number is  supplied,
       it  is  interpreted  as a grey-scale value from black (0) to white (255).  If three numbers are supplied,
       they are interpreted as RGB components from minimum (0) to  maximum  (255).   The  example  above  shades
       weekends a fairly dark grey and makes Mondays a fully-saturated red.  (These shadings appear in calendars
       produced by Rem2PS, tkremind and rem2html.)

       The MOON special replaces the psmoon() function.  Use it like this:

            REM [moondate(0)] SPECIAL MOON 0
            REM [moondate(1)] SPECIAL MOON 1
            REM [moondate(2)] SPECIAL MOON 2
            REM [moondate(3)] SPECIAL MOON 3

       These draw little moons on the various calendars.  The complete syntax of the MOON special is as follows:

            ... SPECIAL MOON phase moonsize fontsize msg

       Phase  is  a number from 0 to 3, with 0 representing a new moon, 1 the first quarter, 2 a full moon and 3
       the last quarter.

       moonsize is the diameter in PostScript units of the moon to draw.  If omitted  or  supplied  as  -1,  the
       backend chooses an appropriate size.

       fontsize is the font size in PostScript units of the msg

       Msg is additional text that is placed near the moon glyph.

       Note that only the Rem2PS backend supports moonsize and fontsize; the other backends use fixed sizes.

       The COLOR special lets you place colored reminders in the calendar.  Use it like this:

            REM ... SPECIAL COLOR 255 0 0 This is a bright red reminder
            REM ... SPECIAL COLOR 0 128 0 This is a dark green reminder

       You  can  spell  COLOR either the American way ("COLOR") or the British way ("COLOUR").  This manual will
       use the American way.

       Immediately following COLOR should be three decimal numbers ranging from 0 to 255 specifying  red,  green
       and blue intensities, respectively.  The rest of the line is the text to put in the calendar.

       The  COLOR  special  is  "doubly  special",  because  in its normal operating mode, remind treats a COLOR
       special just like a MSG-type reminder.  Also, if you invoke  Remind  with  -@[n],  then  it  approximates
       SPECIAL COLOR reminders on your terminal.

       See also the documentation of the $DefaultColor system variable in the section "SYSTEM VARIABLES".

       The  WEEK  special lets you place annotations such as the week number in the calendar.  For example, this
       would number each Monday with the ISO 8601 week number.  The week number is shown like  this:  "(Wn)"  in
       this example, but you can put whatever text you like after the WEEK keyword.

            REM Monday SPECIAL WEEK (W[weekno()])

MISCELLANEOUS

       COMMAND AND KEYWORD ABBREVIATIONS

       The following tokens can be abbreviated:

       o      REM can be omitted - it is implied if no other valid command is present.

       o      CLEAR-OMIT-CONTEXT --> CLEAR

       o      PUSH-OMIT-CONTEXT --> PUSH

       o      POP-OMIT-CONTEXT --> POP

       o      DUMPVARS --> DUMP

       o      BANNER --> BAN

       o      INCLUDE --> INC

       o      MAYBE-UNCOMPUTABLE --> MAYBE

       o      SCANFROM --> SCAN

       NIFTY EXAMPLES

       This section is a sampling of what you can do with Remind.

            REM 5 Feb 1991 AT 14:00 +45 *30 \
            RUN mail -s "Meeting at %2" $LOGNAME </dev/null &

       On  5  February,  1991, this reminder will mail you reminders of a 2:00pm meeting at 1:15, 1:45 and 2:00.
       The subject of the mail message will be "Meeting at 2:00pm" and the body of the message will be blank.

            REM AT 17:00 RUN echo "5:00pm - GO HOME!" | xless -g +0+0 &

       This reminder will pop up an xless window at 5:00pm every day.  The xless window will  contain  the  line
       "5:00pm - GO HOME!"

            REM AT 23:59 RUN (sleep 120; remind -a [filename()]) &

       This  reminder  will  run  at one minute to midnight.  It will cause a new Remind process to start at one
       minute past midnight.  This allows you to have a continuous reminder service so you can work through  the
       night  and  still  get  timed  reminders  for  early  in  the morning.  Note that this trick is no longer
       necessary, providing you run Remind in daemon mode.

            remind -c12 /dev/null Jan 1993

       This invocation of Remind will cause it to print a calendar for 1993, with all entries left blank.

            REM CAL [trigdate()-date(year(trigdate()), 1, 1)+1]

       This example puts an entry in each box of a calendar showing the number (1-365 or 366) of the day of  the
       year.

            REM Tue 2 Nov SATISFY (year(trigdate())%4) == 0
            IF trigvalid()
                 REM [trigdate()] ++5 MSG \
                 U.S. Presidential Election!!
            ENDIF

       This  example  warns  you  5  days  ahead  of each American presidential election.  The first REM command
       calculates the first Tuesday after the first Monday in  November.   (This  is  equivalent  to  the  first
       Tuesday  on  or  after  2  November.)  The SATISFY clause ensures that the trigger date is issued only in
       election years, which are multiples of 4.  The second REM command actually issues the reminder.

       DETAILS ABOUT TRIGGER COMPUTATION

       Here is a conceptual description of how triggers are calculated.  Note that Remind actually uses  a  much
       more efficient procedure, but the results are the same as if the conceptual procedure had been followed.

       Remind starts from the current date (that is, the value of today()) and scans forward, examining each day
       one  at  a  time until it finds a date that satisfies the trigger, or can prove that no such dates (on or
       later than today()) exist.

       If Remind is executing a SATISFY-type reminder, it evaluates the expression with trigdate()  set  to  the
       date  found above.  If the expression evaluates to zero or the null string, Remind continues the scanning
       procedure described above, starting with the day after the trigger found above.

       The SCANFROM clause (having a syntax similar to UNTIL) can modify the  search  strategy  used.   In  this
       case,  Remind  begins  the  scanning  procedure at scan_date, which is the date specified in the SCANFROM
       clause.  For example:

            REM Mon 1 SCANFROM 17 Jan 1992 MSG Foo

       The example above will always have a trigger date of Monday, 3 February 1992.   That  is  because  Remind
       starts  scanning  from  17 January 1992, and stops scanning as soon as it hits a date that satisfies "Mon
       1."

       The main use of SCANFROM is in situations where you want to calculate the positions of floating holidays.
       Consider the Labour Day example shown much earlier.  Labour Day is the first Monday in September.  It can
       move over a range of 7 days.  Consider the following sequence:

            REM Mon 1 Sept SCANFROM [today()-7] ADDOMIT MSG Labour Day
            REM Mon AFTER MSG Hello

       The SCANFROM clause makes sure that Remind begins scanning from 7 days before  the  current  date.   This
       ensures  that  Labour  Day  for  the current year will continue to be triggered until 7 days after it has
       occurred.  This allows you to safely use the AFTER keyword as shown.

       As a special case, you can simply use  a  negative  number  after  SCANFROM;  a  negative  number  -N  is
       interpreted as N days before today.  Thus, the previous example could also be written like this:

            REM Mon 1 Sept SCANFROM -7 ADDOMIT MSG Labour Day
            REM Mon AFTER MSG Hello

       In  general, use SCANFROM as shown for safe movable OMITs.  The amount you should scan back by (7 days in
       the example above) depends on the number of possible consecutive OMITted days that may occur, and on  the
       range of the movable holiday.  Generally, a value of 7 is safe.

       The FROM clause operates almost like the counterpoint to UNTIL.  It prevents the reminder from triggering
       before the FROM date.  For example, the following reminder:

            REM Mon Thu FROM 23 Jul 2007 UNTIL 2 Aug 2007 MSG Test

       will trigger on Mondays and Thursdays between 23 July 2007 and 2 August 2007 inclusive.

       FROM is really just syntactic sugar; you could implement the reminder above as follows:

            REM Mon Thu SCANFROM [max(today(), '2007-07-23')] \
                   UNTIL 2 Aug 2007 MSG Test

       but  that's  a lot harder to read.  Internally, Remind treats FROM exactly as illustrated using SCANFROM.
       For that reason, you cannot use both FROM and SCANFROM.

       Note that if you use one REM command to calculate a trigger date, perform date calculations (addition  or
       subtraction, for example) and then use the modified date in a subsequent REM command, the results may not
       be  what  you intended.  This is because you have circumvented the normal scanning mechanism.  You should
       try to write REM commands that compute trigger dates that  can  be  used  unmodified  in  subsequent  REM
       commands.  The file "defs.rem" that comes with the Remind distribution contains examples.

       DETAILS ABOUT TRIGVALID()

       The  trigvalid()  function  returns  1 if Remind could find a trigger date for the previous REM or IFTRIG
       command.  More specifically, it returns 1 if Remind finds a date not before  the  starting  date  of  the
       scanning that satisfies the trigger.  In addition, there is one special case in which trigvalid() returns
       1 and trigdate() returns a meaningful result:

       If  the  REM  or  IFTRIG command did not contain an UNTIL clause, and contained all of the day, month and
       year components, then Remind will correctly compute a trigger date, even if it happens to be  before  the
       start of scanning.  Note that this behaviour is not true for versions of Remind prior to 03.00.01.

FILES

       The traditional location of your reminders file or directory is:

               $HOME/.reminders

       where $HOME is your home directory.

       Remind  ships  with  some  preinstalled  files for holidays and language packs.  These are located in the
       following directory:

               /usr/share/remind/

       Do not hard-code the above directory in your reminder files.  Instead, use the value of  the  $SysInclude
       system variable.

AUTHOR

       Dianne Skoll <dianne@skoll.ca> wrote Remind.  The moon code was copied largely unmodified from "moontool"
       by John Walker.  The sunrise and sunset functions use ideas from programs by Michael Schwartz and Marc T.
       Kaufman.   The  Hebrew  calendar support was taken from "hdate" by Amos Shapir.  OS/2 support was done by
       Darrel Hankerson, Russ Herman, and Norman Walsh.  The  supported  languages  and  their  translators  are
       listed  below.   Languages  marked  "complete"  support  error  messages  and  usage instructions in that
       language; all others only support the substitution filter mechanism and month/day names.

       German -- Wolfgang Thronicke

       Dutch -- Willem Kasdorp and Erik-Jan Vens

       Finnish -- Mikko Silvonen (complete)

       French -- Laurent Duperval (complete)

       Norwegian -- Trygve Randen

       Danish -- Mogens Lynnerup

       Polish -- Jerzy Sobczyk (complete)

       Brazilian Portuguese -- Marco Paganini (complete)

       Italian -- Valerio Aimale

       Romanian -- Liviu Daia

       Spanish -- Rafa Couto

       Icelandic -- Björn Davíðsson

BUGS

       If you find a bug in Remind, please report it to: dianne@skoll.ca

       There's no good reason why read-only system variables are not implemented as functions, or why  functions
       like version(), etc.  are not implemented as read-only system variables.

       Hebrew dates in Remind change at midnight instead of sunset.

       Remind has some built-in limits (for example, number of global OMITs.)

BIBLIOGRAPHY

       Nachum  Dershowitz  and Edward M. Reingold, "Calendrical Calculations", Software-Practice and Experience,
       Vol. 20(9), Sept. 1990, pp 899-928.

       L. E. Doggett, Almanac for computers for the year 1978, Nautical Almanac Office, USNO.

       Richard Siegel and Michael and Sharon Strassfeld, The First Jewish Catalog, Jewish Publication Society of
       America.

       Jean Meeus, Astronomical Algorithms, Second Edition, Willmann-Bell, Inc.

HOME PAGE

       https://dianne.skoll.ca/projects/remind/

MAILING LIST

       https://dianne.skoll.ca/mailman/listinfo/remind-fans

SEE ALSO

       rem(1), rem2ps(1), rem2pdf(1), tkremind(1), rem2html(1)

4th Berkeley Distribution                          2024-07-26                                          REMIND(1)