Time is the same number of the same time unit, e.g., seconds or milliseconds, for everyone on planet Earth not traveling near the speed of light and who agree how time = 0 is defined. If you are using Java and UNIX, time = 0 is defined as 1-1-1970 GMT.
Synchronization makes good sense does it not? Synchronization is not based on local time zones.
Local time zone is defined on your Operator record. Local time is a conversion; Pega does it for you. There is no difference between converting from GMT to local time and back, than a conversion of binary data to a text string and back, assuming no loss of precision.
As long as a conversion is reversible it does not matter how the information is presented to a human or machine. You could say "local time zone is in the eye of the beholder". It is generally desired for noon to occur when the sun is at its highest point in the sky either directly south or north depending on which hemisphere you are in. But this would not be the case in China which has only time zone.