In today’s super connected world, travel is second nature to most of us. We live and work, physically or mentally in different time zones all the time! In such instances, dual timers are very handy and much preferred. This is where the GMT watch comes in.
In simple terms, a GMT watch is a timepiece with a 24-hour format hand that indicates a second time zone in addition to the other hands and must be noted that this is not just any multiple time zone watch with more than one 12-hour format dial. For a GMT watch, the 24-hour scale is a must.
There is a subtle distinction between a regular dual timer and a pure GMT watch. Although GMT and dual time zone watches often use the same movement, a GMT watch is intended to be set to GMT and left there, while the dual time zone watch is intended to have both zones adjusted more frequently. Then, there is also the world timer, which, by contrast, shows many time zones at once.
The going train in a conventional watch is geared to spin the hour hand around the dial every 12 hours. In a GMT, the second hour hand is geared to run half as fast on an additional 24-hour time scale. Thus, the 24- hour hand circles the dial once a day instead of twice, its tip pointing to the corresponding hour, leaving no confusion as to whether it’s a.m. or p.m. The idea of a GMT watch is to offer two things: a hand that is always synched to GMT time, so that the time all around the world can be identified, and normal hands for local time. Hence, a proper GMT movement allows the hour hand of the watch to be adjusted independentlyso that the GMT hand remains set to the Greenwich Mean Time.
The concept of GMT dates back to 1884 when an international convention declared Greenwich, England as the “Mean Time” against which the rest of the Earth’s time zones would be compared. Those were the days of slow boat travel, and time zones were crossed over days and weeks, not hours.
With the invention of airplanes things changed. It was possible to enter and exit time zones in a matter of hours. This called for special watches which would track time across time zones. Rolex invented the GMT complication and is today the top reference standard for this type of watch. The Rolex GMT Master was one of the classics of this genre and the very first to feature a dual time complication showing home time on a 24 hour display and local time on an independent 12-hour display. The watch was developed in 1954 by Rolex on a specific customer request and was originally designed in collaboration with Pan American Airways and issued by the airline to their crews on long-haul flights.
Over the years, several watch manufacturers have tested the limits and come out with their own GMT watches, each with unique designs and features. The GMT complication has also been incorporated in watches which have other complications, enhancing its reach and appeal. While GMT watches were originally designed for pilots, they are broadly used today by anyone who may be interested in tracking the time in two different places. It is one more unique pointer to the ingenuity of the watch world!