A GMT is up there with one of the most popular luxury watch styles. But what is a GMT watch, and how can you utilize it daily? Find out in this article.
Do you consider yourself a true watch enthusiast? How much do you actually know about the GMT complication? Deepening your knowledge of this watch and its capabilities can further your appreciation for one.
We already know that complications like the chronograph date back to around the early 1800s. If you want, you can read about the history of the wristwatch in more detail.
However, the concept of measuring two time zones at once is much younger. Its history intertwines with sea navigation and air travel.
In this article, we will examine what GMT means and what to use it for in a watch. Then, we will look at how to use and read one. So, without further ado, let’s delve into the history, the use, and the beauty of the GMT watch.
Table of Contents
What Does GMT Stand For?
The name “GMT” is short, punchy, and easy to remember. But what does GMT stand for? The three letters stand for Greenwich Mean Time. The International Meridian Conference in Washington, D.C. selected it as the global reference time in 1884.
Greenwich Mean Time is where time zones start and finish (the Prime Meridian). We split the Earth into 24 time zones, which give us the 24 hours of the day. The first time zone starts in Greenwich (London), and the last ends in Greenwich.
If a time zone in Wellington, New Zealand, is +12 GMT, it means it’s 12 time zones ahead of London. Jamaica, for instance, is -5 GMT. This means that if it’s 5 pm in London, it’s 12 o’clock midday in Jamaica.
The concept was revolutionary at the time. It meant that everyone in the world could operate simultaneously but at their own time. Confusing, huh?
What Is a GMT Watch Good For?
Patek Philippe was quick to respond to the demand for time zone tracking in air travel. You can see evidence of this in its early 1937 Worldtime wristwatch. But the “GMT Boom”, as we know it, didn’t come into play until the 1950s.
The Glycine Airman arrived in 1953 with a rotating 24-hour bezel and 24-hour dial, followed by Rolex’s GMT-Master. This watch, which featured a 24-hour hand, came as a request from Pan AM.
Today, the modern GMT watch has changed very little. The market is plentiful in this complication, offering an abundance of designs in different styles. And you don’t even need to be a regular traveler to enjoy wearing this complication, either. You can use it for all manner of tasks!
You can use it to decide the best time to call a family member or friend in another part of the world. You can also use it at work to organize business meetings with clients overseas.
How To Read a GMT Watch?
This complication tracks an extra time zone via a separate hand. The hand normally correlates to a number out of 24 on a bezel.
To read a GMT watch, it’s essential to understand its anatomy. The basic anatomy of a watch includes parts like the case, crown, bezel, movement, bracelet, lugs, and dial. To delve deeper into the GMT watch, it’s necessary to take a closer look at the dial and bezel.
Some watches are world time complications and display the 24 time zones around the dial flange. A GMT watch, however, shows the time in two different formats via two separate hands.
The fourth hand usually features a contrasting color to the dial and the other three hands. In most cases, you’ll see that the GMT hand has an arrow-shaped tip.
Adding two additional wheels to the watch’s mechanics enables the hand to complete a full revolution daily. The 24-hour scale is usually on the bezel.
A good-quality GMT watch will be legible and easily readable. The hands and hour markers (sometimes the bezel markers, too) will feature luminous material. So, whether working late into the night or traveling on business, times are always easily accessible.
How Does a GMT Watch Work?
Are you wondering, “How does a GMT watch work?”. Let’s break things down.
A GMT movement is different from a conventional time and date movement. The wearer needs to move the additional hand without affecting the natural course of the main hour hand.
To do this, the watch needs two power systems. One controls the hours, minutes, and seconds hand, and the other controls the fourth hand.
The 24-hour hand completes a full rotation every 24 hours. It means that the hand’s cog must rotate at half the speed of the hour hand. Manufacturers add the cog to the movement as an extra.
The main hour hand covers the same distance but within half the time of the GMT hand. This allows the wearer to read two time zones in parallel with one another.
How To Use a GMT Watch?
If you want to know how to use a GMT watch, you must learn how to set it. We already know that the GMT hand works separately from the main hands. You can set it using the crown. It can read a separate time zone once aligned with a reference on the 24-hour track.
And here’s the difference between fixed and moving bezels in a GMT watch. Those with a fixed bezel enable you to track one additional time zone. The arrow-tipped hand aligns with the correlating number on the bezel. This way, it always reads a separate time to the main hands.
A GMT watch with a moving bezel can track more than two time zones effectively. You can set the arrow-tipped hand to the correct position on the dial using the main hour track. This frees up the moving bezel, which you can align with the GMT hand for a third-time zone.
For example, a watch like the TUDOR Black Bay GMT can track three time zones at once. The main hands show local time, while the GMT hand operates independently, aligned with a 24-hour scale for dual time zones.
To set a GMT watch, unscrew the winding crown as you would wind an automatic watch.
Pull it out all the way to set the extra hand.
Then, return the crown to the first position to set the main hour hand.
Push the crown back into the case and screw it down.
Then, rotate the bezel according to the time difference between the 24-hour hand and the third time zone you require.
The Takeaway
The GMT watch is perfect for measuring current time versus an additional time zone in another country. Not to be mistaken for a world-time watch, this complication is simple, legible, and easy to use.
You don’t even need to travel often to enjoy the benefits of one! They’re great for building up your collection with different complications.
Now that you can confidently answer the question, “What is a GMT watch?” you can begin exploring the market. Many reputable brands offer their version of this complication. Choosing the right design is simply down to personal preference.
What’s your favorite GMT watch, and why? Let us know in the comments!
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