A GMT watch is popular among travelers, pilots, and watch enthusiasts who want to keep track of multiple time zones. This extra complication lets you read at least two different times on a single watch face. Today, there are many variations—from vintage-inspired to modern interpretations—and one of the most sought-after automatic movements recently is the NH34 movement.
In this article, we’ll explore how a GMT watch actually works (including some history and practical uses), why the GMT function is so useful, and what characterizes an NH34 GMT movement.
What Is a GMT Watch?
GMT stands for Greenwich Mean Time, historically the reference for global time zones. Today, we typically use Coordinated Universal Time (UTC), but the term GMT lives on in the watch world to describe watches that display an additional time zone.
Key Features of a GMT Watch:
- Extra (fourth) hand: Usually in a distinctly different color to indicate a secondary time zone.
- 24-hour dial or bezel: The GMT hand completes one rotation every 24 hours and is read either on a separate 24-hour index on the dial or via a rotating bezel (ring) marked with 24 hours.
- Multiple time zones: You can typically track local time with the main hands (12-hour display) and another time zone with the GMT hand.
A Brief Historical Background
According to multiple sources, the GMT complication has roots in the 1950s when the Pan Am airline sought an easy tool for pilots and flight crew to track both local time and “home time” (UTC). Rolex GMT-Master, for example, became one of the first watches to use a separate 24-hour hand and a rotating bezel.
How Does a GMT Watch Work?
Unlike standard hour hands—which complete two rotations in 24 hours (one rotation every 12 hours)—the GMT hand rotates exactly once per day. The main hour and minute hands show local time, while the GMT hand (with its 24-hour scale) shows you a secondary time zone.
- Primary Time Zone (Local Time): Shown by the hour, minute, and second hands.
- GMT Time Zone: Shown by the GMT hand. You can set it to home time, a standard time zone like UTC, or any other zone you want to track.
If your watch features a rotating 24-hour bezel, you can effectively monitor a third time zone by adjusting the bezel. Simply rotate it to the time difference you want to track.
The NH34 Movement: A Modern Favorite
One of today’s most popular automatic GMT movements is NH34 (sometimes referred to as Seiko NH34). Here are a few reasons why it has become a favorite:
- Robust Construction: The movement is solid and withstands daily wear without requiring extensive maintenance.
- Easy Adjustment: You can independently set the GMT hand apart from the main hands, making it seamless to switch between time zones.
- Cost-Effective: The NH34 movement is generally more affordable than many Swiss counterparts, without sacrificing functionality or quality.
Who Is a GMT Watch For?
- Business Travelers: Ideal for those who have international meetings or conduct business across time zones.
- Globetrotters: If you travel frequently, you can easily keep track of your home time and local time.
- Pilots and Mariners: Historically developed for pilots who needed to monitor UTC and local time simultaneously.
- Watch Enthusiasts: GMT is a classic complication that’s both aesthetically appealing and practical.
How to Set a GMT Watch (Including NH34 GMT)
- Set the local time by pulling the crown out to the correct position (according to the watch’s instructions).
- Adjust the GMT hand to your desired time zone (home time or UTC) by turning the crown in its dedicated setting mode.
- Rotating bezel (if available): Align the bezel with the correct 24-hour markers to display an additional time zone or to easily determine AM/PM.
Tip: Unsure if the GMT hand is functioning correctly? Check that it completes one full rotation every 24 hours and that it aligns properly with the bezel’s 24-hour markings or the watch’s own 24-hour scale.
Benefits of a GMT Watch
- Versatility: Keep track of both local time and another time zone simultaneously.
- Historical Significance: The GMT complication has an intriguing backstory dating back to the golden age of aviation in the 1950s.
- Practicality for Travel: Switching time zones is easy when crossing multiple regions.
- Aesthetic Appeal: The extra hand adds a distinct design feature to the dial.
- Growing Interest Among Collectors: A robust GMT movement like the NH34 makes the watch even more appealing to watch enthusiasts as a unique investment.
Summary
A GMT watch is more than just a stylish timepiece—it’s a functional tool for anyone who wants to track multiple time zones. With an additional (fourth) hand that completes one rotation every 24 hours and a 24-hour scale, you can easily keep an eye on local time, home time, or another zone you might need.
Choosing an NH34 powered GMT gives you a modern, reliable mechanical movement that offers excellent value. Whether you’re a frequent traveler, conduct international business, or simply love watches with historical charm, a GMT watch will be both functional and stylish—an ideal addition to any collection.
With this, you now have a solid understanding of how a GMT watch—especially with the NH34 movement—functions and why this complication is highly valued by globetrotters and watch enthusiasts alike. Best of luck in your search for the ideal GMT watch. We invite you to explore our selection and see what suits you best.
