In the 1950s, long-distance flying changed the meaning of local time. A traveller could leave one day behind and arrive in another time zone within hours. The need to read home time and local time together was practical, not decorative. Rolex dates the introduction of its GMT-Master to 1955 and places the watch in this era of expanding intercontinental travel. The model later became associated with airlines including Pan American World Airways.
What the extra hand actually does
A conventional watch shows the time around you. A GMT watch adds a 24-hour reference, usually through another hand and a 24-hour scale. Depending on the movement and bezel design, a wearer can keep home time visible while changing the local hour for a trip. The 24-hour scale also makes day and night in the second location easier to distinguish. Different GMT movements set their hands differently, so the experience of changing time zones is worth checking on the exact reference you are considering.
The design became a language
The GMT-Master's two-tone bezel turned a functional day/night distinction into one of watchmaking's most recognisable visual cues. Yet the category is broader than a single bezel or brand. Some GMT watches put the 24-hour markings on a fixed inner ring; others favour a rotating outer bezel. The underlying question remains the same: can you read the second time zone quickly and comfortably?
Leo Gallery's Take
For Canadian owners, the appeal is not limited to international flights. A second time zone can keep a family member's day, a colleague's working hours or a business market in view. We would choose a GMT by the usefulness of its display, how easily its local time can be adjusted, and the watch's fit on the wrist. Historical importance is a compelling story, but it does not automatically make every modern GMT the right daily watch for you.
For a recent example of a distinctive 24-hour display, read our look at the 2026 TUDOR Northflag.
Source
Rolex's official history of 1953–1967 documents the 1955 GMT-Master and its aviation context. This article is Leo Gallery's independent interpretation.
