How to Read a GMT Watch: Track Two Time Zones

A GMT watch lets you check two time zones at a glance. Its regular hour and minute hands usually show local time, while a distinct fourth hand—often tipped with an arrow or colored differently—makes one circuit of the dial every 24 hours. You do not need a special tool; just identify the watch’s 24-hour scale and know the time offset for the other location.

What You’ll Need

A GMT watch with its 24-hour hand and scale visible
The UTC offset for the time zone you want to track, if you are setting or interpreting that zone

Step-by-Step

Identify the GMT hand. Find the extra hand that makes one rotation in 24 hours. It is often arrow-tipped and may be a different color from the hour and minute hands. Do not assume every fourth hand is the GMT hand: check the watch manual or dial markings if you are uncertain.
Find the 24-hour scale. Look for numbers from 1 to 24 around the dial, or for a rotating bezel marked with 24-hour values. Some watches print the scale on an inner ring, so the GMT hand may not point to the same numbers used by the regular hour hand. Read the GMT hand only against its intended scale.
Read the main local time. Use the ordinary hour and minute hands as you would on a standard watch. On many GMT watches, the regular hour hand is set to local time and can be adjusted separately. The GMT hand may keep its own reference time when local time changes, but designs differ.
Read the second zone in 24-hour time. Follow the GMT hand to the 24-hour scale. A reading of 16 means 16:00, or 4 p.m.; a reading of 4 means 04:00, or 4 a.m. The 24-hour scale makes it clear whether it is morning or evening in the tracked location.
Use the minute hand for minutes. On a typical GMT watch, the GMT hand indicates the hour and the regular minute hand indicates the minutes for both time displays. For example, if the minute hand shows 30 and the GMT hand points to 16, the second zone reads 16:30. Confirm your watch’s design, because not all watches use identical displays.
Set the reference zone, if needed. To set the GMT hand, use the watch’s instructions. Many models set it in relation to UTC, while others allow a different reference. Work out the target zone’s offset from the reference, including whether the target is ahead or behind, and account for the date change when crossing midnight.
Adjust the local hour hand for travel, if the watch allows it. On a traveler-style GMT, the local hour hand can often move in one-hour steps without stopping the GMT hand or minute hand. Change it to the destination’s local hour, then check that the date is correct. Other GMT watches adjust differently; follow the manual rather than forcing the crown.
Check the bezel position. If the 24-hour bezel rotates, it can shift the displayed reference time or help compare an additional zone. A misaligned bezel can make a correct GMT hand appear to show the wrong hour. Align it to the watch’s markings or the method described by the manufacturer before relying on the reading.

Common Mistakes

Reading the GMT hand on a 12-hour scale: Its position must be compared with a 24-hour scale. A 12-hour dial alone cannot tell you whether the GMT reading is morning or evening.
Confusing the hands: The extra hand is not necessarily the GMT hand on every design. Look for a 24-hour marking or consult the manual.
Assuming the GMT hand always shows home time: It shows the reference time selected when the watch was set. That may be UTC, home time, or another zone.
Forgetting the date difference: A zone several hours ahead or behind may be on the previous or next calendar day. Check the date as well as the hour.
Using the bezel without checking its position: A rotating bezel changes the reading. Do not assume its zero point is aligned.
Mixing up UTC and local time: UTC is a global time reference, not the local time in every country. The difference between a location and UTC can change when daylight saving time is observed.

Tips

Choose one reference zone and keep the GMT hand set to it; this makes the display easier to remember.
Use a trusted world-time reference when setting a watch or checking an unfamiliar time-zone offset. Account for daylight saving time where applicable.
Think of the 24-hour dial as a full day: the top typically marks 0 or 24, and the numbers progress around to distinguish daytime from nighttime.
If you travel often, learn whether your watch has a caller-style or traveler-style GMT movement. A caller-style model commonly adjusts the GMT hand independently; a traveler-style model commonly adjusts the local hour hand independently. These names describe common functions, not guaranteed features.
Keep the watch manual handy for crown positions, setting order, and date-change cautions. Mechanical and quartz models can have different procedures.

Troubleshooting

The GMT hand seems to show the wrong hour: Check that you are reading the 24-hour scale, and verify the bezel is in the intended position. Then confirm the reference zone and its current offset.
The hour is right but the minutes are wrong: On many models, the GMT hand shares the regular minute hand. If the minute hand is not aligned correctly, set the watch according to its manual.
The time is off by 12 hours: The GMT hand may be on the opposite half of the day. Read the 24-hour number, not just the hand’s position on a 12-hour dial.
The date changes at noon instead of midnight: The watch may be set 12 hours out of phase. Consult the manual to reset the time and date; avoid changing the date during any restricted period stated by the manufacturer.
The crown feels stuck or the hands do not adjust as expected: Do not force the crown. Check the correct crown position and setting method in the manual, or ask a watch service professional if the control remains unresponsive.

Frequently Asked Questions

What does GMT mean on a watch?

GMT refers to Greenwich Mean Time, a time standard historically associated with the zero-degree longitude line. On a watch, “GMT” commonly describes a 24-hour hand that displays a second time zone.

Does a GMT watch show three time zones?

Some can display a third zone by using a rotating 24-hour bezel with the GMT hand. The exact method depends on the watch, and the bezel must be positioned correctly.

How do I tell if the GMT hand shows day or night?

Read its position on the 24-hour scale. Values from 0 through 11 indicate the first half of the day, while 12 through 23 indicate the second half.

Can I use a GMT watch without knowing UTC?

Yes. You can set the GMT hand to another time zone if your watch permits it. Knowing the reference zone and offset helps you set it accurately, but UTC is not required for everyday reading.

Why does my GMT watch have a rotating bezel?

The bezel can let you shift the GMT hand’s reading to compare another zone. On some models it is fixed or serves another purpose, so check the watch instructions before using it.

Further reading: National Institute of Standards and Technology. Details can change, so check the official page for anything that matters to you. Spotted a mistake? Tell us. How we write an answer.