What is a GMT watch and how does it work?
The guide explains what the letters stand for, how to read and set the extra hand, and how the traveler’s and office versions differ. A table compares GMT with world time and dual time, and the conclusion helps you choose the right function for how you travel.
Short answer
A GMT watch displays two time zones simultaneously. In addition to the standard hands, it has an extra hour hand that makes one revolution per day and points to a 24-hour scale on the dial or on the ring around the crystal. The standard hands show the time where you are, and the GMT hand shows the time back home. If the watch has a rotatable 24-hour ring, you can also track a third time zone.
Innehåll · 9 avsnitt
- What is the difference between GMT, world time, and dual time?
- What does GMT mean on watches?
- How does a GMT watch work?
- How do you set a GMT watch?
- How does world time work on a watch?
- What is dual time on a watch?
- Which watch with two time zones is right for you?
- Find a watch with two time zones at Kronura
- Common questions about the GMT function
The letters GMT appear on many dials, but the function behind them varies. In watch stores, three solutions often fall under the same heading: the classic GMT hand, world time, and dual time. All three help you keep track of more than one time zone, but they are read and set in different ways. Here you will find the explanation for each type, how to use it while traveling, and which one is right for you. If you want to see the models right away, they are gathered among our watches with GMT and world time.
What is the difference between GMT, world time, and dual time?
A GMT watch displays a second time zone at all times with an analog 24-hour hand. A watch with world time lets you scroll through the time in a large number of cities. Dual time is a second time that you set yourself and read in an extra display or a small dial. The table shows how the differences are noticeable in practice.
| Feature | GMT hand | World time | Dual time |
|---|---|---|---|
| How the second time is displayed | Extra hour hand pointing to a 24-hour scale | Selected city or time zone in the display | Extra display or small dial |
| Number of time zones | Two, or three with a rotatable 24-hour ring | Many, you choose from a list | Two |
| Changing time zones | Move the hour hand or GMT hand | Select a new city | Set the second time manually |
| Most common in | Analog mechanical and quartz watches | Digital and analog-digital watches | Digital, analog-digital, and simpler analog watches |
| Suitable for you who | Travel between two places and want to see the time back home immediately | Travel to many different countries | Want a simple second time |
| Examples at Kronura | Citizen Series 8 GMT, Bulova Oceanographer GMT | Casio Vintage AE-1000W, Casio G-Shock GA-2100 | Casio Vintage AQ-230 |
What does GMT mean on watches?
GMT stands for Greenwich Mean Time, the mean time at the observatory in Greenwich, London. For a long time, it was the world's common reference time. Today, it has been replaced by UTC, but in everyday life, the two mean the same thing. Time zones are therefore often stated as a difference from GMT: Sweden is on GMT+1 during the winter and GMT+2 during daylight saving time.
On a watch, GMT still refers to the function, not to the time in Greenwich. The GMT hand can be set to any time zone, for example Swedish time when you are in Thailand or the office time when you have colleagues in the USA. The function broke through in the 1950s, when long-distance aviation meant that pilots needed to follow two time zones at the same time. Therefore, GMT is often associated with pilot and sports watches, and in the guide to different types of watches, you can see how they differ from other types of watches.
How does a GMT watch work?
A standard hour hand makes two revolutions per day. The GMT hand is an extra hour hand that only makes one revolution per day. Therefore, it points to a scale with 24 hours, either printed on the dial or engraved on the ring around the crystal. It often has its own color or a pointed tip, so that it is easy to distinguish from the standard hands.
An example: you are in Bangkok and the standard hands show 15.00. The GMT hand is set to Swedish time and points to 9 on the 24-hour scale. Then you immediately know that it is nine in the morning back home during the winter. Since the scale has 24 steps, you can also see whether it is day or night in the other zone, which a standard 12-hour dial cannot show.
Many GMT models have a rotatable ring with a 24-hour scale, and it gives you a third time zone. Rotate the ring by as many hours as the difference between the GMT hand's zone and the third location, and read the time where the GMT hand points on the ring. If the dial also has its own 24-hour scale, you can see the other zone there at the same time. The ring is often two-colored, where one half marks the daytime hours and the other the night. The GMT function is available in both mechanical and quartz watches, and in the guide to automatic and quartz movements, we go through what separates the movements.
How do you set a GMT watch?
There are two types of GMT mechanism, and the difference is noticeable when you arrive. One is often called the traveler's GMT. There, you move the hour hand in whole hours, while the minute hand and GMT hand continue as usual. The standard hands then show the local time and the GMT hand stays on the home time. Bulova Oceanographer GMT has such a separately adjustable hour hand. The other variant is often called the office GMT. There, you instead set the GMT hand separately, which suits you who are at home but want to follow the time in another location. Neither variant is better than the other, they are built for different ways of using the watch.
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Set the home time before you leave
Set the standard hands to Swedish time and check that the GMT hand points to the same hour on the 24-hour scale. If it is 14 back home, the GMT hand should therefore be at 14.
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Set the local time on location
Move the standard hands to local time and make sure the GMT hand still shows the home time. On the traveler's GMT, it is enough to move the hour hand. On the office GMT, you may need to reset the GMT hand afterwards. The instruction manual shows which crown position controls which hand.
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Use the ring for a third zone
If you want to follow another location, rotate the 24-hour ring by as many hours as the difference and read the third time against the ring.
How does world time work on a watch?
World time is the digital solution. Instead of an extra hand, the watch has a list of cities or time zones that you scroll between, and the display shows the time in the city you select. Casio Vintage AE-1000W, for example, covers 31 time zones and has a small world map in the display. The advantage is that you can quickly see the time in many countries without calculating. The disadvantage is that you usually see one city at a time, in its own position that you switch to.
The function is available in many models from Casio G-Shock. On an analog-digital model like the GA-2100, the hands show the time and the small display shows the world time. Watches with Bluetooth, like several models in Casio Edifice, retrieve the time from the mobile app and have hundreds of cities to choose from, so you don't have to set the watch manually.
In the same category, you often find radio-controlled watches. They receive a time signal and set themselves, but a radio-controlled watch does not show a second time zone just because of that. It is the combination with world time that makes them practical for travel.
Casio
G-Shock GA-2100-1AER
€100,95
Se klockan
What is dual time on a watch?
Dual time, in English, means that the watch has a second time that you set yourself, without choosing a city. On analog watches, the second time is often in a small extra dial with 12 hours, and then you do not see whether it is day or night. On digital and analog-digital watches, it is in the display. A typical example is Casio Vintage AQ-230, where the hands show one time and the display can show another.
Dual time is the simplest solution and is often found in quartz watches in the lower price range. It suits you who need a fixed second time, for example for a partner working abroad. Since you set the second time yourself, you also need to adjust it when daylight saving time changes.
Which watch with two time zones is right for you?
Start with how you travel and how you want to read the time. Three questions go a long way.
- Do you mostly travel between two locations? Choose a GMT hand. You see the home time all the time without pressing anything, and the 24-hour scale shows whether it is day or night back home. Citizen Series 8 GMT and Bulova Oceanographer GMT are two automatic examples with a rotatable ring.
- Do you visit many countries? Choose world time. You switch cities instead of calculating hours, and with Bluetooth, the watch handles the time adjustment for you. In our guide to Casio G-Shock, we go through the features in the different series.
- Do you want a simple second time? Choose dual time. It is easy to set, and an analog-digital model gives you both hands and a display in the same watch.
Find a watch with two time zones at Kronura
When you know which function you need, it is easier to choose a model. Among all our watches with two time zones, you can compare GMT models, world time, and dual time side by side. If you are unsure which of the functions a certain model has, our customer service will gladly help you before you order.
Featured watches
GMT and world time from four brands
Three automatic GMT watches with 24-hour displays and an Edifice with world time via Bluetooth.
Citizen Series 8 GMT NB6031-56E
42 mm · 13 mm tjock
Bulova Oceanographer 96B405
41 mm · 14 mm tjock
Casio Edifice Windflow ECB-2200DD-1AEF
48 mm · 11 mm tjock
- ✓ 2 års garanti
- ✓ Äkta märkesklockor
- ✓ 30 dagars öppet köp
- ✓ Fri frakt
- ✓ 4,6/5 på Trustpilot
Common questions about the GMT function
What GMT time does Sweden have?
Sweden is on GMT+1 during the winter and GMT+2 during daylight saving time, which applies from the last Sunday in March to the last Sunday in October. If you have the GMT hand set to Swedish time when you travel, you therefore need to move it one hour when Sweden switches between winter and daylight saving time.
Are GMT and UTC the same thing?
In everyday life, yes. GMT is the mean time in Greenwich and UTC is the modern standard, which is controlled by atomic clocks. The difference between them is less than a second, so for a wristwatch, it does not matter which designation is used.
Why does the ring on a GMT watch have two colors?
The two colors divide the 24-hour scale into day and night. One half covers the daytime hours and the other the night, so that you can see at a glance whether it is day or night where the GMT hand points. The color choice varies between brands and models.
Can a GMT watch show three time zones?
Yes, if it has a rotatable ring with a 24-hour scale. The standard hands show local time, the GMT hand a second zone, and the ring, rotated according to the time difference, a third. Without a rotatable ring, the watch shows two time zones.
Is a GMT watch only for those who travel?
No. The function is just as useful if you have colleagues, customers, or family in another country, or follow sports broadcast from other time zones. Many also choose a GMT model for the look, because the extra hand and the colored ring give the watch a sporty expression.
Does a GMT watch set itself in a new country?
No, a standard analog GMT watch you set manually. Automatic adjustment is available in watches with Bluetooth, which retrieve the time from the mobile, and in some radio-controlled watches that receive time signals in multiple regions.