What is a GMT function and how does it work?

What is a GMT function and how does it work?

A GMT function in a watch allows the wearer to track multiple time zones simultaneously, typically using a 24-hour hand and a rotating bezel or an additional time scale.

How It Works

  1. Standard Hour and Minute Hands – These function like a normal watch, displaying local time in a 12-hour format.
  2. GMT Hand – This additional hand circles the dial once every 24 hours and is typically in a different color for easy readability.
  3. 24-Hour Scale – The GMT hand points to this scale, either on the dial or a rotating bezel, to indicate the second time zone.
  4. Rotating Bezel (Optional) – Some GMT watches have a bidirectional rotating bezel with a 24-hour scale, allowing you to track a third time zone by adjusting it.

How to Use a GMT Watch

  • Two Time Zones: Set the regular hour and minute hands to local time and adjust the GMT hand to your home or reference time.
  • Three Time Zones: If your watch has a rotating bezel, align it with the GMT hand to track an additional time zone.

Popular Uses

  • Frequent Travelers – Helps keep track of home and destination times.
  • Pilots – Originally designed for aviation, as seen in Rolex’s GMT-Master.
  • Business Professionals – Useful for coordinating meetings across different time zones.
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