GMT Watches: Reading the 24-Hour Hand and a Second Time Zone
An editorial guide based on published technical references. Manufacturer examples describe the genuine models in those references; their specifications and certifications do not establish the performance of products listed in this catalog.
A GMT display is easier to understand when you assign each hand a job before changing any settings. Decide which location will be your everyday time and which will remain your reference time.
Two scales, two readings
In the genuine GMT-Master II described by Rolex, the regular hands show local time and the additional hand reads reference time against a 24-hour bezel. The local hour hand adjusts in hourly steps without moving the minute or reference hand, and the date follows local time. The Rolex user guide documents these features; other movements may adjust differently.
A reading exercise
Imagine the minute hand points to six, the regular hour hand lies between ten and eleven, and the extra hand sits halfway between sixteen and seventeen on a neutral 24-hour scale. The readings are 10:30 and 16:30. Read the extra hand against the 24-hour scale, not the twelve large hour markers.
Label those readings “local” and “home” before a trip. Verify the time difference for the actual travel date; seasonal clock changes can make a remembered difference incorrect.
Check adjustment, not appearance
- Ask which hour hand adjusts independently.
- Confirm how the date changes and which crown position controls it.
- Request instructions for the supplied movement, not just the watch it resembles.
A fourth hand in a photograph cannot answer those questions. A demonstration of setting and reading both zones is more informative when comparing listings.
Sources & further reading
References checked on October 17, 2026. This is a research guide, not a hands-on product test.
