The US catches up with most of the rest of the world this weekend with the change to Daylight Savings Time. When the computer is properly configured, Outlook's calendar is unaffected and appointments remain on the correct times.

Problems arise when the time zone is changed after creating appointments. Appointment times change to reflect the new times zone - i.e., when you create an appointment in Eastern TZ for 9 AM then switch to the Pacific TZ, the appointment is no longer at 9AM Pacific, it's at 6AM.

There are two ways to deal with time zone issues - export the appointments to a text file, change the time zone and import, or for short term time zone changes, use Outlook's two time zone feature. Enable it from Tools, Options, Preferences, Calendar options, Time Zone.