- noun one of the 24 parts of the earth in which the same standard time is used
- On the planet earth, a region throughout which the same standard time is utilized. Each is such zone encompasses 15° longitude in width, providing for 24 zones around the globe, each an hour apart. The standard time maintained in many countries and areas does not coincide with the time zone established by these meridians.
- noun one of 24 areas in the world in which the same standard time is used, divided by meridians roughly every 15°