GMT
A GMT is a complication that displays a second time zone with an extra 24-hour hand, normally read against a 24-hour bezel or track. It lets you follow home and local time at once, which is why travellers favour it. The affordable Seiko 5 GMT is one such example.
At a glance
- Extra hand
- A fourth hand makes one full turn every 24 hours
- How it is read
- Against a 24-hour bezel or printed track
- Two styles
- True (flyer) GMT versus office (caller) GMT
The whole point of a GMT is to read two places on a single dial. The usual hour and minute hands show the time where you are, while a fourth hand makes one full turn every 24 hours and points to a second zone, normally read off a 24-hour bezel or printed track.
True GMT versus office GMT
Not every GMT behaves the same way, and the difference shapes how you set it on a journey:
- True (flyer) GMT: the local hour hand jumps on its own in one-hour steps, so on landing you reset local time without disturbing the 24-hour hand
- Office (caller) GMT: the 24-hour hand is the one you adjust, which suits keeping an eye on a distant office or family from home rather than constant flying
Both are honest tools; the right choice simply depends on whether you travel or the people you follow do.
Why travellers keep one
Seeing home and local time at once removes the guesswork, and a GMT manages it without the running cost of a chronograph. It belongs naturally in the complications family, alongside other practical additions you might find on a mechanical watch. For affordable examples, our best Japanese watches guide is a sound place to begin.
Examples
The Seiko 5 GMT is an affordable way to live with the complication, pairing a 24-hour hand and bezel so you can read a second zone at a glance.
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Comparison
The label GMT covers two different mechanisms, and knowing which one you have changes how you set the watch.
| Option A | Option B | Notes |
|---|---|---|
| True (flyer) GMT | Office (caller) GMT | On a true GMT the local hour hand jumps on its own, so you reset local time on landing; on an office GMT you move the 24-hour hand instead, which suits following a distant zone from home. |
Related terms
Watches that show this
Frequently asked questions
What does a GMT watch do?
A GMT shows a second time zone alongside your local time, using an extra 24-hour hand read against a 24-hour bezel or track. That lets you see home and local time at once, which is why travellers find it useful on the move.
What is the difference between a true GMT and an office GMT?
On a true, or flyer, GMT the local hour hand jumps on its own, so you reset local time on landing without touching the 24-hour hand. On an office, or caller, GMT you adjust the 24-hour hand instead, which suits following a distant zone from home.
Is there an affordable GMT watch?
Yes. The Seiko 5 GMT is a well-known affordable example, giving you the extra 24-hour hand and bezel needed to read a second time zone. It is a practical way to try the complication before moving up to pricier travel watches.