what the hell? this is not "just coming to lisp", it's something someone wrote as a personal hack. I upvoted it and commented to encourage more lispers to post here.

Erik Naggum's essay on the subject is highly referenced and cited by people developing time and date libraries for other languages and systems:

http://naggum.no/lugm-time.html

The premiere text on time and date algorithms IS written in Common Lisp:

http://www.amazon.com/Calendrical-Calculations-Millennium-Ed...

And here is a taste of what's out there;

http://www.cliki.net/TIMER http://www.cliki.net/net-telent-date http://www.cliki.net/local-time http://www.cliki.net/Date-Calc http://www.cliki.net/cl-l10n