By default, iCal events are displayed in the main calendar view based on your computer's current time zone (set in Date & Time preferences). You can also choose to view all your iCal events in a different time zone. You may want to change the iCal time zone if you will be traveling to a different time zone and want to see your events shifted to the correct time for the new location.

All the events in the main calendar view are moved to the correct dates and times for the iCal time zone you selected. If you travel back to your original location, choose its time zone from the pop-up menu to see all your events shifted back to their original dates and times.

If you create any new events while the main calendar view is shifted to another time zone, the new events take the time zone of the current view. When you switch back to your original time zone, the events created in the shifted time zone retain the shifted time zone setting. To change an event's time zone, choose a new time zone in the event's Info window. For more information, click "Tell me more."

For information about changing your computer's time zone, search Mac OS Help for "time zone."