GMT
stands for Greenwich Mean Time. It is the standard by which all time is
kept. The world was divided into 24 time zones, starting with
Greenwich, England. Time zones around the world are expressed as
positive or negative offsets of the GMT. GMT watches are inspired by
this important role in global time keeping. Watches provided with the
GMT function are created to help you out when you find yourself many
miles away from home in a different time zone as they simultaneously
display the time in 2 independent time zones. Via a special hand, it
shows the time in the place of departure while the local time is
displayed by the two main hands of the watch.
At
present day there are two major types of timekeepers with the GMT
function. The first one is called world time. The world time watches
feature all 24 time zones and require minimum correction. The second
major type is represented by standard timekeepers with a few independent
counters on the dial. There are also a number of subdivisions relevant
to the timepieces of the latter type.
There are several types of GMT functions. Many have 3 hands:
• A minute hand (makes a full revolution in an hour)
• An hour hand (makes a full revolution in 12 hours)
• A 24 hour hand (makes a full revolution in 24 hours)
Many
also come with an additional bezel marked by minute indicators, hour
indicators, or even the names of different cities. The various
indicators differentiate the time zones. Other GMT-style watches may
come with subdials, have an outer rotating bezel, or they may combine
12- and 24-hour time displays.
If a
quartz timepiece offers the GMT function, it will not influence much
its price. In case of mechanical watch models, the development of a
timepiece with the same function requires considerable changes in the
overall construction of the caliber. Consequently, the timepiece with
the GMT function is priced much higher.