Remind is a full-featured calendar/reminder program featuring sophisticated date calculation, moon phases, sunrise/sunset, Hebrew calendar, alarms, PostScript output, an X front-end, multilingual messages, and proper handling of holidays. It also includes scripts for making a nice WWW calendar server.

Remind is a customizable event reminder program.

a fantastic timer, alarm, calendar, and schedule program that can be accessed from your system tray

To put (one) in mind of something; to bring to the remembrance of; to bring to the notice or consideration of (a person).

put in the mind of someone; "Remind me to call Mother"

assist (somebody acting or reciting) by suggesting the next words of something forgotten or imperfectly learned