What Are GMT Watches?

GMT watches are among the most popular models in the luxury watch segment.

But what exactly are GMT watches and how can they be used in daily life? You'll learn about this and much more in this article.

Do you consider yourself a true watch enthusiast? How well do you know the GMT function? A deep understanding of this watch complication will help you better appreciate its unique capabilities.

It's known that complex functions like the chronograph appeared as early as the beginning of the 19th century. If you're interested, you can delve deeper into the history of wristwatches.

However, the concept of simultaneous time measurement in two time zones is a more recent phenomenon. Its history is closely linked to maritime navigation and the development of aviation.

In this article, we will take an in-depth look at what the abbreviation GMT stands for and why this function is used in watches. Then, we'll explore how to read and use GMT watches correctly. So, let's dive into the history, application, and features of GMT watches.

What Does the GMT Abbreviation Mean?

The name "GMT" is short, concise, and easy to remember. But what exactly does this abbreviation mean? The three letters stand for Greenwich Mean Time. In 1884, at the International Meridian Conference in Washington, it was decided to use this time as a global standard.

Greenwich Mean Time is the starting point for time zones, located on the Prime Meridian. The Earth is conventionally divided into 24 time zones, corresponding to the 24 hours of the day. The first time zone starts in Greenwich (London), and the last also ends there.

If the time zone of Wellington (New Zealand) is designated as +12 GMT, it means it is 12 time zones ahead of London. For example, Jamaica is in the -5 GMT zone, meaning if it is 5:00 PM in London, it is noon in Jamaica.

At the time of its introduction, this concept was revolutionary: it allowed everyone on the planet to work simultaneously but according to their local time. Complex to understand, but an extremely convenient solution.

Why Are GMT Watches Needed?

Patek Philippe quickly responded to the need for air travel to track multiple time zones. This is evidenced by their Worldtime wristwatches from 1937. However, the true "boom" of watches with the GMT function began only in the 1950s.

In 1953, the Glycine Airman model appeared with a rotating 24-hour bezel and a 24-hour scale on the dial. It was followed by the legendary Rolex GMT-Master, developed at the request of Pan Am airlines with an additional 24-hour hand.

Modern GMT watches have hardly changed in design. Many models with this feature are available on the market in various styles. You don't have to be an avid traveler to appreciate the convenience of GMT - these watches prove useful in a variety of situations.

You can determine the optimal time to call a relative or friend in another country. GMT watches are also convenient for organizing business meetings with foreign partners.

How to Read GMT Watches?

The GMT function allows you to track an additional time zone using a separate hand. This hand usually points to a 24-hour scale on the bezel.

To correctly read GMT watches, it's important to understand their structure. The main parts of a watch are the case, crown, bezel, movement, bracelet, lugs, and dial. To understand GMT, you need to look more closely at the dial and bezel.

Some models are equipped with a world time function, displaying all 24 time zones on the flange of the dial. GMT watches show the time in two formats using two different hands.

The fourth hand is usually highlighted in color against the dial background and the other three hands. Often it has an arrow-shaped tip.

An additional two gears are added to the mechanism, allowing this hand to complete a full revolution in 24 hours. The 24-hour scale is usually located on the bezel.

Quality GMT watches have good readability. The hands and hour markers (sometimes markers on the bezel) are coated with luminescent material. This ensures easy reading of time even in the dark, which is important for working at night or during business trips.

How Does the GMT Watch Mechanism Work?

Are you wondering: "How do GMT watches work?" Let's examine the principle of operation.

The GMT mechanism differs from a regular time and date function mechanism. The additional hand needs to be moved separately, without affecting the main hour hand.

For this, watches use two power systems: one for hours, minutes, and seconds, the other for the fourth hand.

The 24-hour hand completes a full revolution in 24 hours, meaning its gear rotates twice as slowly as the hour hand. Manufacturers add this gear to the mechanism as an additional part.

The main hour hand covers the same path in half the time compared to the GMT hand. This allows simultaneous reading of time in two time zones.

How to Use GMT Watches?

To learn how to use GMT watches, you need to know how to set them. We already know that the GMT hand works independently of the main hands and is set using the crown. It shows a separate time zone when you align it with the mark on the 24-hour scale.

There are watches with a fixed and rotating bezel. Models with a fixed bezel allow you to track one additional time zone. The hand with an arrow tip points to the corresponding number on the bezel, showing the time of the second zone.

Watches with a rotating bezel allow you to track more than two time zones. You can set the GMT hand relative to the main time scale, and then rotate the bezel to add a third time zone.

For example, the TUDOR Black Bay GMT model can simultaneously display time in three time zones: the main hands show local time, and the GMT hand shows additional time linked to the 24-hour scale.

Instructions for Setting GMT Watches:

• Unscrew the crown, as if winding automatic watches.
• Pull the crown to the full extension to set the additional hand.
• Return the crown to the first position to set the main hour hand.
• Push the crown back into the case and screw it down.
• Rotate the bezel according to the time difference between the 24-hour hand and the third time zone, if required.

Conclusion

GMT watches are ideal for simultaneously tracking current time and time in another time zone. Unlike watches with a world time function, this complication is easy to use, well-read, and not overloaded with unnecessary features.

You don't have to travel frequently to appreciate the benefits of GMT watches. They are a great addition to a collection and expand the functionality of wristwatches.

Now that you confidently know what GMT watches are, you can start choosing a model. Many reputable brands offer their versions of this function. The choice of a specific design depends on personal preferences.

And which GMT watches do you like and why? Share your opinion in the comments!