GMT bezel
A 24-hour rotating bezel that, with a 24-hour GMT hand, lets the wearer track a second time zone (and a third when rotated).
A GMT bezel is a rotating bezel marked with a 24-hour scale, used together with a dedicated GMT hand to display additional time zones beyond the local time shown on the main dial.
How it works
A GMT watch has a fourth hand (the GMT hand) that completes one revolution every 24 hours instead of every 12. With the GMT hand pointing at the 24-hour markings on the bezel, the wearer reads a second time zone.
Rotating the bezel offsets the GMT hand's reading by a defined number of hours, so a third time zone can be tracked. The classic example: local time on the main dial, home time on the fixed 24-hour scale via the GMT hand, third zone via bezel rotation.
Colour conventions
Two-tone bezels split the 24-hour scale into day and night halves, making AM/PM legibility easier:
- Pepsi (BLRO): red and blue. The classic Rolex GMT-Master colourway since 1955.
- Coke: red and black.
- Batman (BLNR): blue and black.
- Root Beer: brown variants.
- Sprite: green and black.
These nicknames are dealer shorthand and appear in listings and references.
Materials
Vintage GMT bezels were aluminium and faded distinctly with sun exposure (giving rise to highly collectible "ghost" or "fuchsia" bezels on early Submariners and GMT-Masters). Modern Rolex GMT-Master II references use Cerachrom ceramic bezels, which are scratch-resistant and colour-stable.
On other brands
The GMT complication is not Rolex-exclusive. Patek (5990, 5524), AP, Cartier (Pasha GMT), Tudor (Black Bay GMT), and many others produce GMT models. The 24-hour bezel convention is industry-standard.