The following is a scenario of how the Handheld Contact application works when there are multiple time zones involved.

 

(Assuming that the ACT! database is set up on Eastern Time and the device is located on Central Time)

 

If you are in the Eastern Time zone, the appointments would all show up on the handheld exactly as they did on the computer.  Handheld Contact on the PC will sync with GMT and then add the offset to whatever time settings are applied on the PC end.  For example minus 5 hours for Eastern Time.  This is what is synced to the device.

 

If you were in any other time zone (including international), the appointments would all offset with the differential to the Eastern Time zone.  Therefore, if you are in Chicago (Central Time zone) they would all show up an hour earlier, if you are on the West Coast (California), they would show up 3 hours early, if in Germany they would show up 6 hours late.  Based on GMT.

 

The following image may also help: