One of approximately 24 longitudinal divisions of the globe, nominally 15 degrees wide, in which clocks show the same time. Some zones follow the boundaries of states or territories, others differ from neighbouring zones by more or less than one hour. Computers can be programmed to take into account the time zone each user is working in, which is not necessarily the same as the zone the computer is in. See also TZ. (1997-07-20)