First things first, what is a time zone?
Definitions vary, but a time zone is generally understood as a region where the same standard time is used. In other words it’s an area where people are expected to have their clocks in sync.
It can be further defined as an offset from Coordinated Universal Time (UTC), whether to use daylight saving time or not, and if so, when people should set their clocks forward and when they should set it back. (View Highlight)