As I understand it, in aviation and some armed forces, the term Zulu time (denoted by the letter Z) is used to refer to GMT. What is the origin of this? Why the use of "Z"/"Zulu"?
closed as general reference by Jim, kiamlaluno, simchona♦, Mitch, Robusto Jan 9 '12 at 18:05
This question is too basic; it can be definitively and permanently answered by a single link to a standard internet reference source designed specifically to find that type of information. See the FAQ for guidance on how to improve it.
It's all explained in this Wikipedia article. Basically, nothing to do with Zulus in Africa - it's just that in the NATO phonetic alphabet (and amateur radio) contexts, the word for Z is "Zulu".
In the context of Coordinated Universal Time (UTC), Z stands for "zero hours", meaning the offset from Greenwich Mean Time (GMT) is zero. Effectively, Zulu Time is GMT.