Package calendar

Reminder utility

http://www.openbsd.org/cgi-bin/cvsweb/src/usr.bin/calendar

The OpenBSD calendar command is a reminder utility. Calendar reads
a mix of configuration files and standard calendar databases and
then displays lines that begin with either today's date or
tomorrow's. The output of the command shows upcoming events for the
week.

General Commands (Section 1)
calendar
The calendar utility checks the current directory or the directory specified by the CALENDAR_DIR environment variable for a file named calendar and displays...