My Snow Leopard macbook is set to
Set date and time automatically: Apple Americas/U.S. (time.apple.com), but despite sitting idle for several hours (with internet connection), it has yet to do any syncing, the date remains off by ~2 days.
you can go into the system preferences and reset the time manualy, and then set the time to sync automaticly again once you are back up to speed with whatever day/week/month you need. i am not sure why its not syncing with apple, but you can just set the day properly and it will be accurate as long as you dont cross too many time zones.