If you are wondering about WHAT IS A GMT WATCH? then we have all that you need to know.

The GMT function is a function that some watches have that can be very useful, especially for those people who travel a lot or have clients or relatives in a country with a different time zone. 

In the case of travel, this function or complication allows you to quickly obtain the time of origin by pressing a button. Another example is if we have to make a phone call to someone in another country, being able to know the local time will make it easier for us to choose a suitable moment.

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What is the meaning of GMT?

Formerly known as Universal Time, Greenwich Mean Time is the time zone established at the 1884 International Meridian Conference in Washington. 

Based on the Earth’s prime meridian, the GMT was created from measurements of the Earth’s rotation. This meridian runs from the North Pole to the South Pole and crosses the Old Royal Observatory in the London Borough of Greenwich.

The introduction of GMT initially meant the creation of Universal Time, which is the basis for the rest of the world’s local time. One of the objectives was to make sure that maritime traffic and trains arrived on time at that time, and later planes. At that time, the clocks for the seasons were based on different positions of the sun depending on the location. This resulted in some inaccuracies and therefore sometimes delays. 

The GMT function played a particularly important role in transatlantic flights in the 1950s and became even more influential over time.

What does UTC mean?

GMT was used to determine time-based on the sun until 1972. It was finally adjusted to UTC (Coordinated Universal Time). UTC is much more precise because it is based on the time obtained by an atomic clock. Adjusted World Time is a time standard for calculating local time around the world, not a time zone like GMT. 

Some watchmakers, such as IWC and Sinn, use the term UTC instead of GMT to describe their watches in the second time zone, but the two characteristics are the same.

Why do you need a GMT watch?

Nowadays, the possibilities of traveling are easier, and thanks to the GMT function of the watch, you can know the time in different countries. 

It is important to remember that the clock requires programming and this way you can see the time in different parts of the world at a glance.

How do I use the GMT function?

The face of a standard wristwatch typically measures 12-hour intervals. This means that the hour hand turns the dial twice every 24 hours. To indicate GMT, the watch has an additional hour hand, usually arrow-shaped, in a different color than the 12-hour hand. 

Unlike the hour hand, it takes 24 hours for the GMT hand to make a complete revolution of the dial, which is half the speed of the other hand. GMT time is usually indicated by a 24-hour bezel or an ad.

In addition to aesthetics, the GMT watch is especially practical for foreign travelers. 

How to change the GMT time?

As an example we have selected a GMT-MASTER II with GMT, also called the second time zone. 

This watch has an additional hand of another color to differentiate it that allows it to be configured with a time difference from that of the watch. To do this, you must first unscrew the crown. 

Then stretch until placing in the GMT position, at this moment we will set the watch to the hour of the second time zone, always looking at the bezel since it is marked with numbers up to 24 to consider the 24 hours of the day. 

Later we will put the crown in the position of the local time and we will also configure it. A very simple system is to be able to have two time zones and be able to consult them at any time.


The Rolex GMT-Master is probably the most well-known and distinctive GMT watch. Rolex released the first version in 1955 under the name of the former Pan Am Airlines. 

The first transatlantic flight began in the 1950s, allowing people to cross the ocean and the time zone in one day. Pan Am asked Rolex to design a new type of pilot’s watch for pilots. 

The clock must be clearly visible and include additional time zones. The result is the Rolex GMT-Master with the reference number 6542. The GMT-Master and later the GMT-Master II have been in the Rolex catalog since 1955 and have been very successful.

Who created the first GMT watch?

Glycine Airman launched Glycine Airman in 1953. That year, Samuel W, who was a sales representative for Glycine SA at the time. He talked about some of his many flights with different pilots on the optimal characteristics of a pilot’s watch. The answer was that the ideal model would have a second-time zone and would have to be waterproof. As a smart businessman, he immediately passed the idea on to Glycine in Switzerland. In the same year, the developers managed to present one of the world’s first examples, Airman, before Rolex.


Still today GMT is an acronym for Greenwich Mean Time. By default, this should mean that the clock shows Greenwich Mean Time, but the reality is much simpler. 

The GMT format was designed to give travelers a quick idea of ​​where they are in the world. This is because you can only calculate the time in your location if you know the time in Greenwich, England. 

In this way, these watches quickly became popular in the aviation industry because they could indicate when and where the pilot was nearby.

Digital clocks with multiple time zones

With the appearance of digital clocks, this GMT function has been extended with the possibility of storing several time zones. For which you have to click on the configuration until you select the option.

Second-time zone on the dial

The Blancpain Villeret Quantieme Annual GMT supports a dial at 8 o’clock. In this way, this clock shows us the second time zone. Inside it has a manufacture caliber 6054F, an automatic mechanism with annual calendar, GMT, and central seconds functions, and that offers a power reserve of 72 hours. At the bottom of the case, a sapphire reveals the guilloche oscillating weight made of gold.

Why do you need a GMT watch?

Universal time clock

A very interesting variant to the GMTs is universal time watches like the Patek Philippe 5230. The Swiss luxury watch brand has a long tradition of world-time models and is renowned for its legendary aesthetics. That is why now it delights us with the new Universal Time, which renews the concept of the world time clock.

This watch has a dynamic bezel that allows indicating the time of the 24 representative places of each of the time zones in the world, the brand took advantage of this situation to redesign the case, the dial, and the hands in a unique style in the last model.

Why do you need a GMT watch?

The main features of the Calatrava-style case are the protruding wing-shaped bracelet lugs and the fine smooth polished bezel. 

The ring hour hand of earlier models has been replaced by an openwork hour hand whose shape is inspired by the famous “Southern Cross” constellation, while the minutes are cut out in the shape of a rhombus.

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