What is a GMT watch and how does it work?
What does GMT mean?
GMT stands for Greenwich Mean Time. This could be interpreted to mean that your watch shows Greenwich Mean Time, but this is not the case, a GMT watch allows you to have several time zones (2 or more) on a single watch face.
HOW CAN YOU TELL IF A WATCH IS A GMT?GMT watches usually have two hour hands indicating the time and this GMT hand is usually red.
Some watches have a time scale on the bezel or inside the dial itself.
The second time zone is composed of a second hand that rotates around a 24-hour dial.
HOW TO USE THE GMT FUNCTION?The dial of standard wristwatches generally measure a 12-hour time interval. This means that the hour hand turns 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 all the way around the dial and is therefore half the speed of the other hand. The GMT time is visible through the 24-hour bezel.
In addition to their aesthetic appeal, GMT watches are especially practical for those who travel abroad. Thus, a person traveling from Frankfurt to Sydney will have to continually remember that the time difference from 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 is further complicated if that person also has relatives in New York. Thus, a GMT clock will help to avoid this kind of problems in a very simple way.
But let's see specifically with such an example how to use the GMT function in a watch that includes a separately adjustable hour hand.
The different time zones can be set at any time, either while still at home or after landing in Sydney at 20:00. 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 simple steps, you now have three time zones simultaneously.
HOW DID GMT WATCHES COME ABOUT?As the earth revolves around the sun, the light it receives shifts, and although this is now considered a fact, it was unknown until the mid-19th century, and there was no awareness of the time change in the world.
Only in Germany, each of the principalities had its own time. As time went by and with the arrival of the railroads, the existence of so many time zones created chaos as 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 1960s 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 clocks became rapidly popular in the world of aviation, as they were able to show pilots the time of origin and destination.
GMT clocks on a 24-hour basis are used on a large scale in navigation and communications protocols to avoid confusion.
WHY DO YOU NEED A GMT CLOCK?Nowadays, the possibility to travel 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 watch must be programmed, and thus at a glance you can know the time in different parts of the world.