calendar(1)
NAME
calendar − reminder service
SYNTAX
calendar [ − ]
DESCRIPTION
The calendar command consults the file ‘calendar’ in the current directory and prints out lines that contain today’s or tomorrow’s date anywhere in the line. Most reasonable month-day dates such as ‘Dec. 7,’ ‘december 7,’ ‘12/7,’ etc., are recognized, but not ‘7 December’ or ‘7/12’. If you give the month as “*” with a date, i.e. “* 1”, that day in any month will do. On weekends ‘tomorrow’ extends through Monday.
When an argument is present, calendar does its job for every user who has a file ‘calendar’ in his login directory and sends him any positive results by mail(1). Normally this is done daily in the wee hours under control of cron(8).
The file ‘calendar’ is first run through the “C” preprocessor, /lib/cpp, to include any other calendar files specified with the usual “#include” syntax. Included calendars will usually be shared by all users, maintained and documented by the local administration.
RESTRICTIONS
The calendar’s extended idea of ‘tomorrow’ doesn’t account for holidays.
FILES
calendar
/usr/lib/calendar to figure out today’s and tomorrow’s dates
/etc/passwd
/tmp/cal*
/lib/cpp, egrep, sed, mail as subprocesses