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What is a GMT watch and how does it work?

The GMT function is a very useful complication, especially for those who travel very frequently, as it allows you to quickly check both the time of the place you are visiting and the time of the place of origin.

What does GMT time mean?

GMT stands for Greenwich Mean Time. This could be interpreted as your watch showing Greenwich Mean Time, but this is not the case, a GMT watch allows you to have multiple time zones (2 or more) on a single watch face.


GMT watches usually have two hour hands that indicate the time and this GMT hand is usually red.
Some watches have an hour scale on the bezel or within the dial itself.
The second time zone is made up of a second hand that rotates around a 24-hour dial.


The dial of standard wristwatches generally measures a time interval of 12 hours. This means that the hour hand circles the dial twice within 24 hours. To indicate GMT, the watch has an additional hour hand, typically arrow-shaped and of a different color than the 12-hour hand. Unlike the hour hand, the GMT hand takes 24 hours to go around the dial and, therefore, its speed is half that of the other hand. GMT time is seen through the 24-hour bezel.

In addition to their aesthetic appeal, GMT watches are especially practical for those traveling abroad. Thus, a person traveling from Frankfurt to Sydney will have to continually remember that the time difference with respect to the local time in Germany is 8 hours and, therefore, when they arrive in Australia, they will always have to be calculating the time from the time in Germany. This becomes even more complicated if said person also has relatives in New York. In this way, a GMT watch will help avoid these types of problems in a very simple way.

But let's see specifically with this example how to use the GMT function in a watch that includes a separately adjustable hour hand.

You can set the different time zones at any time, whether while still at home or once you land in Sydney at 8:00 p.m. Simply set the GMT hands on the dial to European time (12:00). Then also set the hour hand to Sydney local time (20:00). To set New York time, move the 24-hour bezel (GMT hand) to the corresponding New York time (6:00). With these short and easy steps you will now have three time zones simultaneously.


As the earth rotates around the Sun, the light it receives moves and although this information is currently considered a fact, until the mid-19th century it was unknown, and there was no awareness of the change in time in the world.
Only in Germany, each of the principalities had its own time. As time went by and with the arrival of railways, the existence of so many time zones generated chaos since more than 30 different time zones had to be considered.
In 1884, after endless negotiations, an agreement was reached to divide the Earth into 24 time zones and the Greenwich Mean Time, GMT, was established as “zero” time.
In the sixties this was replaced by UTC, Universal Time Coordinated, whose main feature is the use of the division of the day into 24 hours based on time zones.
The GMT format was invented in watchmaking so that travelers could quickly know the time anywhere in the world. These watches quickly became popular in the world of aviation, as they were capable of showing pilots the time of their place of origin and destination.
GMT clocks based on 24 hours are widely used in navigation and communication protocols to avoid confusion.


Nowadays, the possibility of traveling has been facilitated, and thanks to the GMT functionality of the watch you can know the time in different countries.
It is important to remember that the clock must be programmed, and that way with a glance you can know the time in different parts of the world.