The leave tool, common on the IBM AIX operating system and Berkeley Software Distribution (BSD) systems is excellent for when you are working at the command line for long hours and you want a reminder for a meeting or just when you have to leave for the day.
Just pass leave the time when you have to leave, using a 24-hour format: HHMM. It runs in the background, and five minutes before that given time, it outputs on your terminal a reminder for you to leave. It does this again one minute before the given time if you're still logged in, and then at the time itself -- and from then on, it keeps sending reminders every minute until you log out (or kill the leave process).
For example, you can enter leave +0800 to be reminded to leave in 8 hours. Below I entered a reminder to be scheduled after 2 minutes. You can see that background process is kicked off and continues to notify me until I logout.
cooper:~ scotbuff$ leave +0002
Alarm set for Sat Oct 21 14:57. (pid 6316)
cooper:~ scotbuff$ Just one more minute!
cooper:~ scotbuff$ Time to leave!
Time to leave!
Time to leave!
Because you can pass the time to leave as an argument, leave could be useful in scripts as well.
