All you need to know about GMT watches – and why Patek is king
On the website greenwichmeantime.com there is a page dedicated to time apps. Here you can create a list of different cities at the touch of a button, see the time in Chizhou, Sidoarjo or Scaggsville, USA concurrently and compared to your home time. You can check whether meetings in different time zones have been properly coordinated. You can check sunrise and sunset anywhere in the world, and the same for the lunar rising and setting. With all this at the flick of a finger, why would you want a GMT watch?
But the fact is, we do. At Watches and Wonders, the annual luxury jamboree held in Geneva, there were GMT and travel watches for every taste and budget. There was minimalism at Parmigiani Fleurier, with its elegant take on a dual time, featuring a subtle gold hand that remains hidden until it is required. Montblanc used a red dot for its second zone indication in its 1858. Patek Philippe gave its version of a retro aviation vibe. TAG Heuer’s take is a racy little automotive-inspired number in a Carrera case. Even Nomos, more known for its Bauhaus austerity, added this particular complication to its Club Sport Neomatik line.
Lydia Winters on the GMT
“Wristwatches give us a sense of time, but GMTs and world-timers connect us to places,” says Lydia Winters, brand consultant, watch collector and co-host of the This Watch Life podcast. “For me, this is the most useful complication for everyday life. Whether traveling and wanting to know the time at home or – often in my case – living across the world from my family as an American in Sweden, wearing a GMT or world-timer brings them closer because I always can see their time. It’s an important point of connection. It’s the bridge between the poetic – a feeling of connection to home – and the practical.”
This mix of the practical and the poetic was how the complication came to be in a wristwatch in the first place. The first world-timer was created by Louis Cottier at a time when travel was the preserve of the elite. Even if one did travel, there was little need to know what the time was back home because letters were the main form of communication. As the son of a watchmaker, Cottier had more knowledge than most, so, just two years after completing training, he was able to put his mind to solving the problem of how to display multiple time zones on a dial.
By 1931 – 38 years after the International Meridian Conference in Washington where the world was divided into 24 time zones with Greenwich as point zero – he had a solution in what he termed his “Heures Universelles” or HU. The local time was displayed as usual with the three central hands, but he linked the 12-hour hand to a 24-hour ring on which the cities’ names were written. It rotated counterclockwise, a half rotation for every full turn of the hour hand. As the hours progressed, the inner ring would move with it so the wearer could easily read the time in any part of the world.
For years this complication was confined to pocket watches, albeit ones commissioned by the likes of Vacheron Constantin. Then Patek Philippe came knocking and Cottier was called upon to downsize his invention. In 1937, he put a world time in a rectangular ref. 515 HU and in a Calatrava case for the ref.96 HU. The latter became one of the most collectible watches in the world and Cottier had paved the way for the classic world time still used by Patek Philippe and later adopted by Patek alum Svend Andersen.
“Back in the 1980s, when Svend Andersen launched his first collection – the Communication – a world time was an essential complication for businesspeople and frequent travellers, offering a practical way to track multiple time zones,” explains CEO Pierre-Alexandre Aeschlimann. “More importantly, it was a complication Svend mastered during his years at Patek Philippe in the 1970s, where he worked closely with the legendary Louis Cottier world time mechanism.”
While these world times of Andersen and Cottier were romantic and artistic, the next big leap was more functional than aesthetic, using the bezel as an indicator. The first person to pioneer that was Glycine with the Airman, which debuted in 1953 and featured a 24-hour display paired with a rotating bidirectional bezel marked with a 24-hour scale. This was a professional pilot’s watch, the idea being that, with a bezel indication, they could quickly set and read a second time zone. Unfortunately for Glycine, two years later Rolex unveiled its GMT-Master, and the design code of a new GMT was set.
What is a GMT?
But what exactly is a GMT watch? Technically there are two types – the true GMT and the office or caller GMT. On a true GMT the 12-hour hand can be adjusted independently, making it ideal for frequent travellers who need to reset their watches when changing time zones. An office GMT has an independently adjustable 24-hour hand for those who just need a secondary time zone, so they know when to call the office.
However, given that we now have all that information at the tap of a screen, why are people still spending their money on outmoded complications? It all goes back to that personal connection. “In 2025, the practical necessity of a world time complication on a mechanical watch has diminished, much like the perpetual calendar, moon phase, or chronograph,” says Aeschlimann. “Yet, the world time remains a beautiful complication, one that resonates with collectors globally and connects them through a shared appreciation of horological artistry.”
That connection is something that resonates with Winters. “What I love about Nomos’s new Club Sport neomatik Worldtimer, which aims to be a go anywhere, do anything world timer, is being able to have the second time zone on the subdial,” she says. “It’s a new configuration of the traditional world time dial layout, and I’ll always have it set to Florida. It’s nice to be able to look down at my wrist and know what time it is for my sister and nephews. Is it breakfast time there? Are they just getting out of school? Is it time for us to FaceTime yet? It adds an extra connection with the people that matter most in my life.” The practical combined with the poetic. You can’t get that from an app.
