Scroll through any list of the best watches for men and you’re sure to come across a GMT watch. OMEGA, Rolex and Tudor? They all do GMT models. But what is a GMT watch and how does it differ from a standard three-handed timepiece? Simply put, a GMT watch has a fourth hand. And yes, you’ve guessed it, the additional hand displays Greenwich Mean Time. This allows you to manage more than one timezone, with the GMT hand measuring a standard time that is independent of your current time zone.
Specifically, GMT stands for Greenwich Mean Time (Greenwich being a borough of London), which is basically ground zero for time zones across the world, or the time zone from which all the others scale either up (+) or down (-). So what does that make a GMT watch? Well, it makes it a watch that can tell time in two (or more) separate time zones simultaneously. Let’s break it all down below.
History of the GMT Watch
While the concept of a 24-hour day goes all the way back to ancient Egypt, and Greenwich Mean Time was first introduced in 1884, the GMT watch officially kicked off during The Jet Age, i.e. the era in which commercial airlines began flying overseas. Along with the new possibilities in air travel, there came some unexpected surprises. Jet lag was one of them. Pilots losing track of the time back home was another.
While travellers are still figuring out how to outmanoeuvre jet lag to this day, Rolex was on top of the time zone issue. And who better for the job? As a brand already synonymous with steadfast functionality at both high altitudes and under the sea, Rolex wasted no time churning out the GMT-Master in 1954. Hosting an iconic Pepsi-coloured bezel, the GMT-Master had the unique ability to relay two separate time zones at once. As the years progressed, more GMT watches emerged, and soon enough it wasn’t just the pilots wearing them, but the passengers too.
What is a GMT Watch and How Does It Work?
In the simplest sense, a GMT watch is one that’s equipped with a GMT complication, a complication being any function that goes beyond the watch’s ability to tell time (in one time zone, that is). Hence, while a regular watch keeps 12-hour time, the Rolex GMT-Master added a rotating 24-hour bezel and a second, arrow-shaped hour hand to the dial. Under the skin, a complication was added to spin the second hour hand once per day, as opposed to twice.
How Does a GMT Watch Work?
The basics are quite straightforward. The normal watch hands tell the time in a 12-hour format, rotating the dial twice a day. The extra GMT hand displays the time in a 24-hour format and circles the dial once every 24 hours. The standard hands correspond with the numbers or markers on the dial and the GMT hand points to a 24-hour scale – usually on the bezel. For clarity, the GMT hand is often colourful and has a prominent pointer, so you should be able to read each timezone at a glance.
Once you’re comfortable with the concept behind a GMT watch, you shouldn’t have too much trouble operating one. Remember, the GMT hand records the world’s standard time. It’s basically the zero marker on which all 24 international time zones are based. Modern GMT watches have what’s known as a true GMT complication so you can quickly set the GMT hand to Greenwich Mean Time. Then you can set the standard hour hand to your local time – Sydney is GMT +11 for example. If you’re feeling adventurous you can play about with the two sets of hands and bezel to view the time in up to three timezones.
Who Makes the Best GMT Watches?
There’s stiff competition to be crowned best GMT watch, with most well-known brands offering this popular complication. At the affordable end, you can’t go wrong with Seiko’s recent SKX Sports Style GMT Series, but for us, the original is still the best.
Rolex’s GMT-Master was the first ever GMT watch and the current iteration – the GMT-Master II – is hard to beat. It boasts classic Rolex styling and outstanding workmanship and features some iconic colourways. Our favourites are the blue and black Batman model and Clint Eastwood’s famous choice, the brown and gold Root Beer edition.
How to Use a GMT Watch
Remember: Greenwich Mean Time is ground zero for time zones. That means you can measure the time zone you’re currently in by how many hours that time zone is away from GMT. For example, if your time zone is one hour up from GMT, then you first set the bezel to GMT time, and then rotate up one hour. Voila! The second-hour hand is now following your second time zone on a 24-hour scale. Of course, if you know how to read 24-hour military time, it might save you a step or two.
What is the Meaning of GMT?
GMT refers to the British town of Greenwich, London and its selection as the location for the world’s mean time. In the late 1800s, the Royal Observatory in Greenwich was chosen as the place from which all other time zones were measured. Greenwich Mean Time is zero and the other 23 timezones are plus or minus this (measured in hours). So Tokyo is GMT +9 and New York is GMT -5. GMT allows the world to operate on an agreed standard time.
Who Still Uses a GMT Watch?
With technology now always within arm’s reach, GMT watches don’t invoke the same sense of utility or urgency that they once did. Nevertheless, the best GMT watches remain consistently desirable among collectors. So it’s no wonder that brands like Rolex occasionally revive the GMT-Master, complete with the Pepsi dial.
Meanwhile, GMT watches can still theoretically fulfil a need, permitted you don’t resort to modern technology. Indeed, whether you’re a frequent flier, a businessman who depends on variables (stock markets, etc.) in alternate time zones, or someone with loved ones across the world, you can rotate your bezel accordingly and keep your finger on the pulse on simultaneous time zones. Or you can just Google it. Whatever works for you.
When it comes to watches, GMT stands for Greenwich Mean Time and refers to Greenwich, London, the location of the Royal Observatory. In 1884 the International Meridian Conference selected Greenwich as the location for the world's mean time. Greenwich is hour zero and all the other time zones are measured, plus or minus, against this. Sydney is eleven hours ahead of Britain so it is GMT +11.
The practical advantage of GMT watches is that they allow users to display Greenwich Mean Time and their current time zone. With the additional use of a rotating bezel, it's also possible to calculate a third time zone.
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