It seems that the date/time information transmitted by the cellular network (and used to synchronize the time between the Network and BB) includes the following components:
1) GMT time and date
2) local DST adjusted time and date
Can someone confirm that GMT is really included and if so, is it always transmitted by all carriers (US/Canadian/Asian CDMA and European/Asian GSM carriers).
I was playing around with the world clock "TrackIt TimeZone Edition" from Javatek Media
and there was no way to fool it that I was in a different time zone than the real one. No matter what Time Zone I set in BB in Options - Date/Time (Hawaii, Dubai, whatever), the world clock somehow knew that I was really in US EST and it was always calculating the same, correct time and date for all selected cities.
The only explanation seems that the cell tower is transmitting time in GMT or that it is transmitting the time zone code.
My BB date/time settings are as follows: http://img9.imageshack.us/img9/2971/09162009101936.png