A GMT watch is a clever piece of engineering designed to show multiple time zones at once. At its heart, it uses an extra 24-hour hand and, often, a rotating bezel. The standard way to use it is to set that distinctive 24-hour hand to your home time (or a reference time like GMT) and the main hour hand to wherever you are in the world. This simple, functional solution has made it a favorite tool for travelers for decades.
Why a GMT watch is more than just a timepiece
Before diving into how to set hands and turn bezels, it’s worth appreciating what makes a GMT watch special. It is not just another complication, it is a piece of watchmaking history, born from a real-world need during the golden age of air travel. The design is a study in functional simplicity, solving a complex problem with thoughtful mechanics.
This setup lets you keep life in sync across different longitudes. You might be coordinating with a team on another continent, or you just want to know if it's a good time to call home without waking everyone. For many, this practical function makes it one of the best travel watches available.
A tool born in the skies
The story of the GMT watch is tied directly to the dawn of international jet travel. The name itself, GMT, stands for Greenwich Mean Time, the world's time standard. This type of watch was developed to help people keep track of multiple time zones, a feature that became essential in the 1950s as transatlantic flights grew common.
The most famous example is the Rolex GMT-Master, created in 1954 for Pan Am pilots who needed a way to track their home time zone while knowing the local time at their destination. This history underscores that the GMT watch was designed from the ground up as a purpose-built instrument. Every part has a job.
To help you get familiar with the key elements on the dial, here is a quick breakdown:
Anatomy of a GMT watch
| Component | Primary Function |
|---|---|
| Main Hour Hand | Indicates the current local time on the 12-hour scale. |
| 24-Hour (GMT) Hand | Points to a second time zone (usually home time) on the 24-hour scale. |
| Rotating Bezel | A movable ring with 24-hour markings, used to track a third time zone. |
| Date Window | Displays the current date, which is linked to the local (main) hour hand. |
Understanding these parts is the first step to mastering your GMT watch.
A GMT watch is fundamentally about connection. It connects you to home when you're away, to a colleague across the world, and to a rich history of exploration and engineering.
Understanding its lasting appeal
Beyond its clear utility, the GMT watch holds a unique place among collectors and enthusiasts. It carries a spirit of adventure and a link to a global community. For those who appreciate the history and value of their pieces, managing your watch collection with care can deepen that connection.
The mechanical ingenuity required to display multiple time zones without cluttering the dial is a testament to the art of watchmaking. This blend of history, function, and design makes learning to use a GMT watch so satisfying.
The initial setup: mastering home and local time
Setting up your GMT watch correctly from the start is the key to getting the most out of it. Once you understand the logic, it’s quite simple. The idea is to establish a solid reference point, your 'home' time, and then have the freedom to adjust your 'local' time independently as you move.
First, get to know your watch's crown. On most GMTs, you unscrew it (if it's a screw-down type) and then pull it out to different positions or 'clicks'. The first click usually lets you adjust the date and the 24-hour hand, while pulling it out to the second position typically stops the watch and allows you to set the main time. Spending a minute familiarizing yourself with this is time well spent.
Your main goal here is to set the 24-hour hand to your home time. This hand is the anchor, the one constant in your timekeeping, no matter where you are. The main hour and minute hands, on the other hand, will always show the time wherever you currently are.
Establishing your home and local time
Let's walk through a practical scenario. Imagine you live in Zagreb and you are about to fly to New York. Zagreb is your 'home' base, and New York will be your 'local' time.
Your first move is to set the 24-hour hand to Zagreb time. If it’s 16:00 (4 PM) in Zagreb, pull the crown out to its first position and turn it until that distinct 24-hour hand points directly at '16' on the bezel or the 24-hour scale on the dial. Your home time is now set.
Now, let's get your local time sorted. Pull the crown all the way out to the second position. This lets you adjust the main 12-hour and minute hands. Since New York is six hours behind Zagreb, you’d set these hands to 10:00 (10 AM). Just like that, you can see both time zones at a quick glance.
This infographic gives a great visual breakdown of the key parts you'll be using.
It really helps to see how the dial, GMT hand, and bezel all work together to track multiple time zones.
A quick note on the date function
Here is a common point that can be confusing, as the date function is always tied to your local time. This is a critical detail. The date on your GMT watch will only change when the main 12-hour hand passes midnight in your current location.
When you are setting your watch, always make sure the date reflects your local time, not your home time. For example, if you are in Los Angeles but home is in Zagreb, it might be a different day in each place. Your watch's date should show the date for Los Angeles.
This functionality is what makes the GMT one of the most useful watch features, known in the watch world as a complication. If you are keen to learn more about the mechanics behind these clever features, this detailed guide to watch complications and how they work is a great resource. Understanding what's going on inside deepens your appreciation for the machine on your wrist.
Using the rotating bezel to track a third time zone
Once you are comfortable tracking home and local time, you can start using your GMT watch’s other main feature, tracking a third time zone. This is where the rotating bezel comes in, turning your watch into a powerful tool for global coordination without needing to touch the crown.
Let's walk through another real-world scenario. You are based in Zagreb, but you’ve just landed in London for meetings. Your watch is set up perfectly, as the main hands show London time, while the GMT hand points to Zagreb time on the 24-hour scale. Then you get an email, you need to join a call with the team in Tokyo.
This is the bezel’s moment to shine.
How to set the third time zone
First, you need to know the time difference between your reference time (what the 24-hour hand is set to) and your target third zone. In our example, the 24-hour hand is tracking Zagreb (UTC+2). Tokyo is UTC+9. A quick calculation tells us Tokyo is seven hours ahead of Zagreb.
Now, all you do is rotate the bezel seven clicks counter-clockwise (to the left). Each click on most GMT bezels represents a one-hour jump. That simple action has offset the bezel's 24-hour scale. Your 24-hour hand hasn't moved, as it is still pointing to Zagreb time, but it is now also pointing to the correct hour for Tokyo against the newly adjusted bezel.
Just like that, you can read three time zones at a single glance:
- Local Time (London): Read from the main 12-hour hands.
- Home Time (Zagreb): Read from the 24-hour hand against the dial's fixed markers.
- Third Zone (Tokyo): Read from the 24-hour hand against the rotated bezel.
This on-the-fly calculation is what makes a GMT so useful. For professionals across Europe, this functionality is a great convenience for international business and travel. It is a feature that has helped keep mechanical watches relevant, a trend you can see in broader market trends in the watch industry.
The beauty of the rotating bezel is its mechanical immediacy. It's a tactile, analog calculator on your wrist that lets you navigate the world's time zones without reaching for your phone.
Bidirectional vs unidirectional bezels
It is worth noting that almost all GMT watches have a bidirectional bezel, meaning you can turn it both clockwise and counter-clockwise. This makes adjustments quick, as you just turn it whichever way is shorter.
This is a stark contrast to dive watches, which have unidirectional bezels as a safety feature to prevent a diver from accidentally underestimating their time underwater. A bidirectional bezel is purely for convenience, a subtle but important detail that shows how GMTs are built for the global traveler. Mastering this feature is what separates someone who just wears a GMT from someone who truly uses it.
Putting your GMT watch to work in the real world
Knowing how a GMT watch works is one thing, but the real value comes when you start applying it to your own life. This isn't just a watch for pilots and globetrotters anymore, it is a genuinely useful tool for anyone living in an interconnected world. These watches shine when they solve a real problem, whether that is coordinating international business or just knowing when to call home.
Let’s look beyond the basic travel scenario and see how different people can set up their GMT to make their lives a little easier. You'll quickly see just how flexible this complication is.
Juggling time zones for business
Picture this, you are based in Zagreb, your company's head office is in London, and your biggest client is in Dubai. Trying to keep those three time zones straight in your head is a recipe for a late-night call or a missed meeting. This is where a GMT watch becomes a reliable tool.
A smart way to set it up would be:
- Local Time (Main Hands): Set to your current location, Zagreb (CET).
- Home Time (24-Hour Hand): Point this to London time (UTC), which serves as your company's anchor.
- Third Zone (Rotating Bezel): Spin the bezel to track Dubai's time (UTC+4).
With that setup, one glance at your wrist gives you the time in all three critical locations. While the watch provides an elegant, at-a-glance solution, for juggling multiple schedules, a digital meeting planner for time zones can be a great complementary tool.
Staying connected with home
If you are an expat living abroad, your GMT watch can be more than a tool, it is a connection. Imagine you moved from New York to Zagreb. Your priority isn't coordinating business, but knowing the right time to phone family and friends back in the States.
The setup here is wonderfully simple:
- Local Time (Main Hands): Zagreb time.
- Home Time (24-Hour Hand): New York time (EST/EDT).
Now, that 24-hour hand isn't just tracking another zone, it is your 'family time' hand. It tells you instantly if you are about to wake someone up or if they are just sitting down for dinner. It is a small touch that makes a big world feel more connected.
Seeing your home time on your wrist isn't just about data, it's a comforting anchor. It is knowing, at a glance, whether your loved ones are just starting their day or winding down for the evening.
To illustrate how versatile these watches are, here are a few more common ways people set up their GMTs based on their needs.
Common GMT watch use-cases
| User Profile | Home Time (GMT Hand) | Local Time (Main Hands) | Bezel Use-Case |
|---|---|---|---|
| Frequent Flyer | Home city (e.g., Zagreb) | Destination city (e.g., New York) | N/A (or third zone for a layover) |
| Remote Worker | Main office HQ (e.g., London) | Their own local time (e.g., Zagreb) | Tracking a key client's time zone (e.g., Dubai) |
| Pilot/Crew | UTC/Zulu Time | Local time of arrival/departure | N/A (UTC is the standard reference) |
| Day Trader | NYSE opening time (EST) | Their own local time | Tracking London or Tokyo market hours |
These examples show that there is no single "right" way to use a GMT. It is about making it work for your specific routine and priorities. The watch adapts to you.
This kind of practical functionality is a big reason for the enduring popularity of mechanical watches. In the European market alone, which made up around 30% of Swiss watch exports in a recent year, an impressive 78.5% of that value came from mechanical timepieces.
If these scenarios have you thinking about adding a GMT to your collection, our guide to the best GMT watches under 1000 is a good place to find some excellent options.
Common mistakes and how to avoid them
Getting the hang of a GMT watch is rewarding, but even experienced owners can run into a few common pitfalls. Think of this as friendly advice to help you sidestep small mistakes that can cause confusion or even damage your watch's movement.
It is surprisingly easy to misread the 24-hour hand at a quick glance. Since it only sweeps around the dial once a day, you have to be mindful of AM versus PM. For example, when the GMT hand points to the '6' on the bezel, is that 6 in the morning or 18:00 in the evening? An easy way to orient yourself is to remember the top half of the bezel (from 6 to 18) generally represents daylight, while the bottom half is night.
Avoiding mechanical mishaps
Here is a crucial piece of advice, respect the mechanics, especially when it comes to the date. Most mechanical watches have a ‘danger zone’, typically between 9 PM and 3 AM. During these hours, the watch's internal gears are starting to engage to flip the date over.
Forcing a manual date change while the main hour hand is in this late-night window can put stress on the movement and potentially damage it. A good habit is to first move the hands to a safe position, like 6:30, before you pull the crown out to set the date.
It is a simple, two-second precaution that shows mechanical sympathy and will go a long way in keeping your timepiece healthy.
Daylight saving time and other quirks
Lastly, let's talk about Daylight Saving Time (DST). Your watch is a marvel of engineering, but it can't magically account for clocks springing forward or falling back. That part is up to you.
- If DST changes in your local time zone: You will need to adjust your main 12-hour hand forward or back an hour.
- If DST changes in your home or second time zone: You will have to adjust the 24-hour hand (or the bezel, if you are using it) to reflect that change.
Forgetting this is a classic way to find yourself an hour off without realizing why. It is a small bit of manual work a couple of times a year, but it is part of the charm of owning a proper mechanical travel watch. It keeps you engaged and connected to the rhythm of time across different parts of the world.
Got questions about your GMT? Let's get them answered
Even after you get the hang of your GMT, some specific questions almost always come up. It is the little details and quirks that make these watches so interesting. Let's tackle a few of the most common ones.
What is the deal with ‘flyer’ vs ‘caller’ GMTs?
This is a great question because it gets right to the heart of how different GMT movements are designed. It all comes down to which hand you can adjust independently.
A ‘flyer’ GMT, often called a ‘true’ GMT by collectors, is built for the globetrotter. With this type, you can jump the main 12-hour hand forward or backward in one-hour increments, all without stopping the second hand. It is incredibly practical. When you land in a new city, you just adjust the main hour hand to local time, while your 24-hour hand keeps ticking away, faithfully tracking home time.
Then you have the ‘caller’ GMT. Here, the 24-hour hand is the one you can set independently. This setup is perfect if you generally stay in one place but need to keep tabs on another time zone, maybe you are coordinating with an office in London or, as the name suggests, 'calling' family overseas. You set your local time like any other watch and then position the GMT hand to point to the hour in that second zone. One isn’t better than the other, they are just designed for different lifestyles.
How do I track time zones with 30 or 45-minute offsets?
This is a classic challenge for anyone working with places like India (UTC+5:30) or parts of Australia. Your standard mechanical GMT is geared for full-hour jumps, so it can't natively handle those partial-hour time zones.
There is a simple workaround. The key is to remember that your watch's minute hand is the same for every time zone you are tracking. All you need to do is set the 24-hour hand to the correct hour for that location and then use your regular minute hand to read the minutes. It takes a little mental math, but you get used to it quickly. For India, you would just know you are always 30 minutes past the hour shown by the GMT hand.
The GMT hand is all about the hour. Your main minute hand does the rest of the work, staying constant no matter which time zone you’re glancing at.
Does my GMT watch handle daylight saving time?
In a word: no. A mechanical watch is an intricate piece of engineering, but it can't automatically account for the shifting dates of Daylight Saving Time (DST). Those changes vary all over the world, which is too much to ask from a collection of gears and springs.
This just means you will need to give your watch a quick manual adjustment a couple of times a year. When the clocks spring forward or fall back in either your local or reference time zone, you will have to update the right hand yourself. It is a little ritual that keeps you in tune with your watch and the rhythm of time.