I just spent a bit of time head scritching why the heck the
calendar I created in iCal didn’t work correctly. After searching
around I finally stumbled on the answer on Apple’s site.
The problem centers around if you had your computer in another timezone
and then moved to another timezone and created a calendar then tried to
publish it. Sometimes the old timezone gets stuck. This causes
issues when you try to publish to .Mac as it reports the wrong timezone
when you view it.
You can find Apple’s Answer here.