Short answer: a GMT watch shows a second time zone using an extra hand that circles the dial once every 24 hours, read against a 24-hour scale on the bezel or dial. Set the normal hands to local time and the GMT hand to home time, and you can read both at a glance; a rotating 24-hour bezel even lets you track a third zone. ChronoSeasons currently lists 18 GMT and travel watches, from $290 automatics to Swiss quartz aviation tributes.
What "GMT" means
GMT stands for Greenwich Mean Time, the historical reference time at the Royal Observatory in Greenwich, London, from which world time zones were measured. In watch terms, "GMT" has become shorthand for any watch that tracks a second time zone with a 24-hour hand. The complication became closely linked with aviation once long-haul flights made crews cross several zones in one working day, which is why so many GMT watches carry pilot-watch styling.
How a GMT hand and 24-hour bezel work
A normal hour hand goes around the dial twice a day. The GMT hand goes around once, so it points to a position on a 24-hour scale, numbered 0 or 24 at the top and 12 at the bottom. That scale tells you whether it is 3 in the afternoon or 3 in the morning at home, which a 12-hour dial cannot.
- Set local time with the hour and minute hands, as on any watch.
- Set the GMT hand to the hour in your second zone, using the 24-hour scale.
- Read both: the main hands give local time; the GMT hand against the bezel gives home time. Minutes are shared, because almost all time zones differ by whole hours.
- Add a third zone (rotating bezel only): turn the bezel by the hour difference, and the GMT hand now reads a third zone against the shifted scale, while the fixed inner markings, if present, still give the second.
A fixed 24-hour bezel is simpler and cannot be knocked out of position. A bi-directional rotating bezel adds that third-zone trick. Two-color bezels (often blue and black, or blue and red) split day and night hours so you can tell at a glance whether it is daytime in the other zone.
True GMT vs caller GMT
Mechanical GMT movements come in two broad types, and the difference lies in which hand you can adjust on its own.
| "True" or flyer GMT | "Caller" or office GMT | |
|---|---|---|
| Independently adjustable hand | Local hour hand, in one-hour jumps | GMT (24-hour) hand, in one-hour jumps |
| What you change when you land | Jump the local hour hand; the watch keeps running and the GMT hand stays on home time | Reset the main hands to local time, then reset the GMT hand to home time |
| Date | Usually follows the local hour hand, forward and back | Follows the main time |
| Best for | Frequent flyers changing local time often | Tracking a fixed second zone, such as colleagues or family abroad |
In daily wear both do the same job: show two zones at once. A true GMT is more convenient when you change zones every few days; a caller GMT is perfectly practical if you mostly stay put and keep an eye on another city. If a specific model's movement type matters to you, ask us before you buy and we will check the setting procedure for that reference.
Mechanical or quartz GMT?
Our GMT watches split between self-winding automatics and Swiss quartz. The Bersigar Luxaura models use automatic GMT calibers (the Seiko NH34A or the Pearl DG5833 / Pearl DG, depending on edition) that wind from wrist motion and need no battery. The Bristol tributes use Swiss quartz movements with GMT and date functions: more accurate day to day and easy to grab after a week in a drawer. Our automatic vs quartz guide covers the trade-offs in detail.
GMT and travel watches at ChronoSeasons
- Bersigar Luxaura 1706 Black Blue GMT: 40mm brushed steel, Pearl DG5833 GMT automatic, bi-directional rotating 24-hour bezel, 100m; from $290.
- Bersigar Luxaura 1682 Black Dial: 40mm, fixed brushed steel 24-hour bezel and an orange GMT hand, Pearl DG5833 GMT automatic; from $339.99.
- Bersigar Luxaura 1662 Black Blue Jubilee: split black and royal blue 24-hour rotating bezel, five-link bracelet, Seiko NH34A GMT automatic; from $339.99.
- Bersigar Luxaura 1662 Left Side Crown: a "destro" layout with crown and date at 9 o'clock for left-wrist comfort, black and emerald bezel; from $339.99.
- Bristol P-51 Mustang Tribute GMT: 44mm, Swiss quartz with GMT and date, P-51D airframe artifact in the caseback, limited to 1,945 units; from $447.
- Bristol F/A-18 Hornet Tribute GMT: 44mm gunmetal steel, Swiss quartz with date and GMT, limited to 1,978 units; from $397.
- Bristol B-17 Flying Fortress Tribute GMT: 44mm polished steel, beige dial, Swiss quartz with GMT function and original B-17 airframe material in the caseback; from $447.
On a tighter budget, the Hemel Navigator tracks a second time zone with its bezel rather than a GMT hand, in a 40mm no-lug case with a Seiko VH31 quartz, from $199.99. Browse more in Field & Adventure, pilot and aviation watches and the Expedition season.
How to choose a travel watch
- How often do you change zones? Weekly flights favor a true GMT; a fixed second zone suits a caller GMT or quartz GMT.
- Fixed or rotating bezel? Fixed is cleaner and tamper-proof; rotating adds a third zone.
- Size and bracelet: the Luxaura models are 40mm, the Bristol tributes 44mm. See our watch size guide.
- Water resistance: 100m on the Luxaura range covers swimming; 50m on the Bristol tributes suits rain and handwashing.
Questions we get
What is a GMT watch used for?
Tracking a second time zone, such as home time while traveling or the time where colleagues work, alongside local time.
Can a GMT watch show three time zones?
Yes, if it has a rotating 24-hour bezel. Rotate the bezel by the hour difference and read the GMT hand against it for a third zone.
What is the difference between a true GMT and a caller GMT?
On a true GMT you jump the local hour hand independently; on a caller GMT you adjust the 24-hour hand independently. Both display two zones.
Why are GMT bezels two colors?
The split marks daytime and nighttime hours on the 24-hour scale, so you can see at a glance whether it is day or night in the other zone.
Is a quartz GMT worth considering?
Yes. A Swiss quartz GMT, like the Bristol tributes, is accurate, low-maintenance and ready to wear without winding.
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