calendar -- appointment calendar<hr>
This is the calendar reminder utility from the NetBSD distribution. It can
be used in two different ways. When a non-root user runs calendar without
any arguments, it examines the user's calendar file, (the location is
specified by the CALENDAR_DIR environment variable), and displays the
user's appointments for that particular day. When run by root with the
-a option, calendar examines the calendar file in the login directory
of each user on the system, and sends a reminder of any appointments
to the user by mail. This will done for you every night by cron,
(see /etc/cron.daily/calendar.cron).  This binary may be redistributed,
provided the Copyright notice is included in the distribution, (provided
in the associated /usr/doc directory).
</listing>