Free tool
Where do I set the GMT hand?
A GMT hand tracks a second time zone on a 24 hour scale. Pick your home zone and the one you want to track, and see exactly where the fourth hand should point right now.
Blue = GMT hand (24h)
How a GMT hand actually works
The fourth hand rotates once every 24 hours rather than every 12, which is what lets it distinguish morning from evening in the second zone without ambiguity. Read against a 24 hour scale, either printed on the bezel or on the dial's inner ring, it gives you a complete second time.
There are two mechanical types and the difference matters when you travel. A true GMT, sometimes called a flyer or caller depending on which hand jumps, lets you move the local hour hand independently in one hour steps while the GMT hand keeps running. An office GMT moves the GMT hand independently instead, leaving the main hands untouched.
For actual travel you want the independent local hour hand, because on landing you set your new local time in seconds without stopping the movement or losing your home reference. For tracking a colleague in another country from your desk, the office style is fine and usually cheaper.
Using the bezel for a third time zone
If your GMT has a rotating 24 hour bezel, you get a third zone for free. Leave the GMT hand on your home time, then rotate the bezel by the offset you want and read the GMT hand against the moved bezel.
This is why the 24 hour bezel exists and why pilots valued it. With the hour hand on local time, the GMT hand on UTC and the bezel rotated to a third offset, one watch shows three zones simultaneously with no complications beyond a rotating ring.
Fixed bezel GMTs cannot do this, which is one reason models with rotating bezels command higher prices on the secondary market even though the movement inside is often identical.
Daylight saving is the thing that catches people out
GMT watches do not know about daylight saving. Offsets shift twice a year in most of Europe and North America, on different dates, and a watch set correctly in February will be an hour out in April without anything having gone wrong mechanically.
The offsets in this tool are standard time offsets and do not adjust for summer time. If the zone you are tracking is currently observing daylight saving, add an hour.
It is also worth knowing that not all offsets are whole hours. India runs at UTC+5:30, Nepal at UTC+5:45 and parts of Australia at UTC+9:30, which no GMT hand can display precisely since the hand moves in hour steps. For those zones the GMT hand gets you close and you remember the rest.
Common questions
How do you set a GMT watch?
Set the GMT hand to your home time on the 24 hour scale, then set the main hour hand to local time. On a true GMT the hour hand jumps in one hour steps independently, so you can change local time on landing without disturbing the GMT hand or stopping the movement.
What is the difference between a caller GMT and a flyer GMT?
On a flyer, or true GMT, the local hour hand moves independently in one hour jumps, which is what you want for travel. On a caller, or office GMT, the GMT hand is the one that moves independently, which suits tracking another zone from home.
Can a GMT watch show three time zones?
Yes, if it has a rotating 24 hour bezel. The hour hand shows local time, the GMT hand shows a second zone, and rotating the bezel lets you read a third against the same GMT hand.
Does a GMT watch adjust for daylight saving?
No. Offsets change twice a year on dates that differ by country, and the watch has no way to know. You have to move the hand or the bezel yourself when the clocks change.
Related tools
Which GMT is it?
Upload a few photos and get model identification, an authenticity verdict and a market valuation in under 30 seconds.
Scan your watch