This is not my project. It is a command line tool that I love and have used for many years. I wanted some place to back it up in case the official homepage ever disappeared.

http://www.roaringpenguin.com/products/remind

Remind

Remind is a sophisticated calendar and alarm program. It includes the following features:

• A sophisticated scripting language and intelligent handling of exceptions and holidays.
• Plain-text, PostScript and HTML output.
• Timed reminders and pop-up alarms.
• A friendly graphical front-end for people who don't want to learn the scripting language.
• Facilities for both the Gregorian and Hebrew calendars.
• Support for 12 different languages.

Command Line and tcl/tk tool.