Everything you need to know about the GMT watch: history and operation
The term "GMT" may seem enigmatic at first, but it actually refers to one of the most useful, fascinating, and iconic complications in watchmaking history. A true icon on the wrists of seasoned travelers, aviators, and mechanical enthusiasts, the GMT watch transcends eras without ever showing its age.
But where does this complication come from? How does it allow you to read multiple time zones simultaneously? And above all, how do you choose the right GMT watch for your adventures?
Discover everything you need to know about this timekeeping instrument, as well as the presentation of our new
What is a GMT watch and where does this term come from?
To understand this complication, we must go back to the origins of its name. The acronym GMT stands for Greenwich Mean Time. It is the mean solar time calculated at the Greenwich meridian, which passes through the famous Royal Observatory located near London.
From train races to air corridors
For centuries, each city and region set its time according to the local path of the sun. With the advent of the railway in the 19th century and then the explosion of transcontinental civil aviation after World War II, traveling long distances quickly made this system chaotic. In 1884, the Earth was therefore divided into 24 uniform time zones, using Greenwich as the prime meridian.
Although GMT was officially replaced in 1972 by UTC (Coordinated Universal Time), the name GMT has remained deeply embedded in watchmaking culture to designate watches capable of simultaneously displaying two distinct time zones.
How does a GMT watch work?
On a traditional three-hand watch, the hour hand completes a full rotation of the dial in 12 hours. A GMT watch is distinguished by the presence of a fourth hand.
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The fourth hand (24-hour hand): Often dressed in a contrasting color and equipped with a specific arrow, it completes a full rotation of the dial in 24 hours (compared to 12 hours for classic hands).
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The flange or the 24-hour graduated bezel: The GMT hand points to a scale from 0 to 24 hours. This allows you to instantly know whether it is 4 a.m. or 4 p.m. in the monitored time zone, thus eliminating any confusion.
Day/Night .
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Simultaneous monitoring: The main hands indicate your local time (where you are), while the GMT hand continuously points to the reference time (your home, your company's headquarters, or a relative abroad).
Why adopt a GMT watch for everyday use?
Far from being a mere gadget, the GMT complication offers numerous advantages:
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Stay connected with your loved ones or your business: No more mental calculations about whether you can call without waking up those around you or send a work email at the right time.
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A high-value mechanical complication: Seeing four hands move in harmony on the same dial is a testament to fine watchmaking technique.
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A sporty and sleek aesthetic: With its distinctive hand and characterful bezel, the GMT watch displays a strong visual personality.
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A backup compass: For outdoor orienteering enthusiasts, by pointing the hour hand towards the sun in the Northern Hemisphere, the bisector between the hand and the noon marker indicates the direction of South.
New Concordia GMT: The spirit of adventure in the world
At Charlie Paris, we design our watches as true companions for life, designed and assembled in France. With our new
Technical specifications designed for extreme conditions:
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Japanese Seiko NH34 automatic movement: Recognized worldwide for its endurance, precision and shock resistance, this modern mechanism offers a proven GMT complication and high-performance automatic winding.
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Case 40.5 mm thick 316L steel: Ergonomic and balanced proportions, designed to suit all wrists, for everyday use as well as on the field.
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Exceptional water resistance 30 ATM (300 meters): Equipped with a screw-down crown, the
Concordia GMT braves the rain, deep immersions and challenging nautical sessions without flinching.
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Unidirectional rotating bezel & Sapphire crystal: A scratch-resistant sapphire crystal to protect against impacts, combined with a precise bezel to measure your times or orient your reference points.
- Super-LumiNova® readability: Luminescent indexes and hands ensure clear and instantaneous reading, even in the dark of night or underwater.
Absolute versatility on your wrist
Because your days alternate between travel, urban appointments, and sports sessions, the new
Pair it as you wish with a waterproof rubber for water sports, a technical nylon ultra-lightweight for sports, or A
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