GMT watches are among the most practical complications in modern watchmaking. Originally developed for pilots and international travelers, GMT watches allow the wearer to track multiple time zones simultaneously using an additional hand and a 24-hour reference scale.
Today, GMT watches remain popular among travelers, aviation professionals, military personnel and anyone who regularly communicates across multiple time zones.
At Forge & Crown, GMT watches represent one of the most versatile categories of commissioned timepieces because they combine everyday practicality with mechanical complexity and distinctive design.
What Does GMT Mean?
GMT stands for Greenwich Mean Time.
Historically, GMT served as the world's primary time reference standard and was based on the Royal Observatory in Greenwich, England.
While Coordinated Universal Time (UTC) is now the official international standard, the term "GMT" remains widely used throughout the watch industry.
A GMT watch allows the wearer to track:
- Local time
- A second time zone
- Sometimes a third time zone when paired with a rotating GMT bezel
How Does a GMT Watch Work?
A GMT watch uses an additional hand that rotates once every 24 hours rather than once every 12 hours.
This hand is typically distinguished by:
- A different color
- An arrow-shaped tip
- Increased visibility
The GMT hand is read against a 24-hour chapter ring, a 24-hour bezel, or a dedicated GMT scale. Because the hand completes one full rotation every 24 hours, it clearly distinguishes between day and night in the second time zone.
Why Were GMT Watches Created?
The first GMT watches were developed during the growth of international commercial aviation.
Pilots frequently crossed multiple time zones and required a reliable method of tracking departure time, destination time, and coordinated aviation time (UTC or Zulu).
GMT watches quickly became standard equipment among airline crews, military aviators and long-distance travelers. Today, the complication remains popular because of its practical utility.
Common Uses for GMT Watches
- Travelers — Track local time while maintaining awareness of home time
- Aviation Professionals — Monitor UTC (Zulu) time while tracking local destination time
- International Business Professionals — Coordinate meetings and communications across multiple regions
- Military Personnel — Maintain UTC reference time while deployed in different locations
- Watch Enthusiasts — Appreciate the mechanical complexity and functionality of GMT complications
Types of GMT Watches
Modern GMT watches generally fall into two categories.
Caller GMT
A caller GMT allows the GMT hand to be adjusted independently while the local hour hand remains synchronized with the minute hand. Examples include the NH34, DG3804, and ETA 2893-2. Caller GMT movements are ideal for individuals who primarily remain in one location while monitoring another time zone.
Traveler GMT
A traveler GMT allows the local hour hand to jump independently without stopping the movement. Examples include the Miyota 9075 and Rolex 3285. Traveler GMT movements are often preferred by frequent travelers because local time can be adjusted quickly when changing time zones.
GMT Watches with Rotating Bezels
Many GMT watches include a rotating 24-hour bezel, allowing the wearer to track local time, a second time zone, and a third time zone. By rotating the bezel, the GMT hand can reference an additional time zone beyond its primary setting. This functionality is particularly useful for international travelers and aviation professionals.
Automatic vs Quartz GMT Watches
Both mechanical and quartz GMT watches provide excellent functionality.
Automatic GMT Watches
Advantages: mechanical operation, traditional watchmaking appeal, no battery changes, enthusiast appeal. Examples: NH34, DG3804, Miyota 9075, ETA 2893-2.
Quartz GMT Watches
Advantages: higher accuracy, lower maintenance, lower ownership costs, excellent travel reliability. Examples: Ronda 515.H24, Ronda 505.24H.
Both approaches offer compelling advantages depending on the wearer's priorities.
Builder Ecosystem & GMT Platform Availability
Not all GMT movements are equally suitable for commissioned watch projects. Movement selection involves more than functionality. Builders must also consider case availability, dial availability, hand availability, replacement movement sourcing, long-term support, and warranty considerations.
The strongest GMT movement is not always the most expensive GMT movement.
Common GMT Movement Platforms
| Movement | Type | Buildability Rating |
| NH34 | Caller GMT | A |
| Miyota 9075 | Traveler GMT | B |
| ETA 2893-2 | Caller GMT | B |
| Ronda 515.H24 | Quartz GMT | B |
| DG3804 | Caller GMT | C |
Forge & Crown Buildability Ratings
NH34 — Rating A
The strongest overall balance of functionality, affordability, parts availability and long-term support.
Miyota 9075 — Rating B
Excellent traveler GMT functionality, but a smaller ecosystem and higher acquisition cost.
ETA 2893-2 — Rating B
Premium Swiss caller GMT movement with strong performance but more limited sourcing options and higher costs.
Ronda 515.H24 — Rating B
Highly practical Swiss quartz GMT movement offering excellent accuracy and low maintenance.
DG3804 — Rating C
Interesting entry-level GMT option, but with a smaller ecosystem and greater long-term sourcing uncertainty.
Choosing the Right GMT Platform
Choose NH34 if: you want an automatic GMT, prioritize parts availability, want long-term support, or want the largest ecosystem.
Choose Miyota 9075 if: you travel frequently, want a true traveler GMT, or independent local-hour jumping is important.
Choose ETA 2893-2 if: you prefer Swiss movements, premium positioning is important, or budget is less of a concern.
Choose DG3804 if: lowest-cost automatic GMT ownership is the primary goal and you understand ecosystem limitations.
Choose Ronda 515.H24 if: accuracy is a priority, low maintenance is important, or you prefer quartz reliability.
Which GMT Watch Is Best?
There is no universally superior GMT movement.
The best GMT watch depends on travel frequency, budget, mechanical vs. quartz preference, long-term service expectations, and desired watch style. The right movement is the one that best matches the owner's intended use.
Forge & Crown Perspective
At Forge & Crown, GMT watches remain one of the most practical complications available in modern watchmaking.
When evaluating GMT movements, we look beyond technical specifications and focus on long-term viability: Can replacement movements be sourced? Can compatible cases, dials and hands be obtained? Can the watch realistically be supported years after it is built?
Those questions matter just as much as power reserve or jewel count.
For most commissioned GMT projects, the NH34 currently represents the strongest balance between capability, support, affordability and long-term serviceability. Premium options such as the Miyota 9075 and ETA 2893-2 remain excellent choices for specific use cases, while the DG3804 offers an interesting entry point for enthusiasts seeking affordable mechanical GMT ownership.
Learn more about how we approach movement selection during the commissioning process.
Frequently Asked Questions
What is a GMT watch?
A GMT watch is a watch capable of tracking multiple time zones simultaneously using a dedicated 24-hour hand.
What does GMT stand for?
GMT stands for Greenwich Mean Time.
How many time zones can a GMT watch track?
Most GMT watches track two time zones. Models with rotating 24-hour bezels can often track a third.
What is a GMT hand?
A GMT hand is an additional hand that completes one full rotation every 24 hours and displays a second time zone.
Why does a GMT hand use a 24-hour scale?
The 24-hour scale allows the wearer to distinguish between daytime and nighttime hours in the second time zone.
What is the difference between a caller GMT and a traveler GMT?
A caller GMT adjusts the GMT hand independently. A traveler GMT adjusts the local hour hand independently.
Is the NH34 a caller GMT?
Yes. The NH34 is a caller GMT movement.
Is the DG3804 a caller GMT?
Yes. The DG3804 is generally classified as a caller GMT movement.
Is the Miyota 9075 a traveler GMT?
Yes. The Miyota 9075 is one of the most accessible traveler GMT movements available today.
Who benefits most from a GMT watch?
Travelers, pilots, airline crews, international business professionals, and anyone who regularly interacts with multiple time zones.
Are GMT watches difficult to set?
No. Most GMT watches are straightforward to set once the wearer understands how the GMT hand functions.
Why does Forge & Crown offer GMT watches?
GMT functionality is one of the most practical complications in modern watchmaking. It adds genuine utility while maintaining simplicity and reliability.
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Related Reference Articles
- NH34 GMT Movement: Technical Specifications, Compatibility Guide, and Alternatives
- DG3804 GMT Movement: Technical Specifications, Compatibility & Performance Guide
- GMT Movements Compared: DG3804 vs NH34 vs Miyota 9075 vs ETA 2893-2
- NH34 vs DG3804 GMT Movement Comparison
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