If you keep iCal's icon in your dock the date on the icon is always wrong until you launch iCal. So, I wrote a simple script to launch and quit iCal:
tell application "iCal"
activate
quit
end telland saved it as an app in my applications folder as 'dockiCal.app'. Then I added this line to the end of my /etc/crontab file using the pico editor:0[tab]0[tab]*[tab]*[tab]*[tab]root[tab]cd /Applications/ ; open ./dockiCal.app[robg adds: replace [tab] with a press of the tab key]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20030214163614514