There are 24 letters in the alphabet and 24 time zones (oh, I know, but "I" and "O" don't count as they look too close numbers)
As I understand it, there are actually 26 time zones corresponding to the 26 letters of the alphabet. 360 degrees, divided by 15 degrees per time-zone, gives 24 time zones, as Dan Dare correctly states, but there are a couple of obscure places in the world (ok, so they're probably not that obscure, but I can't remember where they are off the top of my head) that work on time zones that are XX hours and 30 minutes ahead/behind Zulu time, and that's where the other two come from. Someone please correct me if I'm wrong, though.
FFF
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