GMT
A function that displays a second time zone, usually with an additional hand read against a 24-hour scale.
Also known as: Greenwich Mean Time, GMT function, GMT watch
Definition
A GMT watch provides a second time-zone indication, typically using an additional hand that makes one revolution every 24 hours and is read against a 24-hour scale. The name comes from Greenwich Mean Time, but the complication is used for any chosen second zone. Some movements allow the local 12-hour hand to jump independently; others independently set the 24-hour hand. A rotating 24-hour bezel can add a third zone when the hand and bezel are used together.
Why it matters
The setting architecture matters to travellers: an independently jumping local hour is especially convenient when crossing time zones, while other GMT designs suit monitoring a remote zone from home.