UNIX Calendar

Reviewed by Brian White 4/25/2012

The UNC Computer Science department has a special reminder program installed on all of its UNIX systems.  The program is called "calendar", and its main use is to have email reminders sent to you, based on a file listing events about which you wish to be reminded.  This article describes how to get set up to use the calendar file, what the reminder program does, and what to put in the calendar file.

Getting set up

For the reminder service to work, you need to make a file called "calendar" in the "public" subdirectory of your home directory. In addition, the directory containing the calendar file must be readable by the computer that is checking for calendar files.

Everyone's AFS home directory was initially set up with a "public" subdirectory with the proper permissions for the calendar program to work. If you have changed things around, you can execute this command:

/usr/local/bin/fs setacl ~/public cs-machines rl

What the reminder program does

The reminder program runs at 4:00 a.m. every day. It looks in your public/calendar file and sends you email with all the lines from your public/calendar file that match either today's or tomorrow's date. On Fridays and Saturdays, it also sends you lines that match the following Sunday and Monday, since you might not read mail over the weekend.

What to put in the calendar file

The calendar program recognizes dates in several different formats:

2/15 matches February 15 of any year
tuesdays matches Tuesday of any week
2/15/05 matches February 15 of any year (year is ignored)
* 15 matches the 15th of any month

Examples of the kinds of things you might want to put in the calendar file:

2/16 Meet with Joe Smith
tuesdays staff meeting at 10:00 in SN155
2/17/15 announce plans to run for president
* 15 run monthly report
4/25 get car inspected by 4/30
6/30 get fireworks for 7/4
7/26 Mick's birthday
1/15 4/15 7/15 10/15 turn in quarterly report

The date can be anywhere in the lines, but for organizing your calendar file it helps to keep the dates on the left.

Note that the ability to recognize days of the week is a local modification of the standard UNIX calendar program.