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Understanding The World Time Watch
A tale as old as time zones.
The world time watch, like the diver’s watch, and the pilot’s watch, is a product of the industrial revolution and the advances in technology that went along with it. Unlike a GMT complication, the world time watch shows the time not just in two or three different time zones, but in at least 24 different time zones, spread around the world. While it’s true that you can more or less guesstimate the time in different time zones if you’re adept at mental arithmetic (and if you know the offset from GMT in the time zone in question) the world time watch takes all of the guesswork out of the process, showing you – at a glance – the time across the entire planet.
The History Of The World Time Complication
The history of world time watches as we know them begins with the establishment of the system of international time zones, which is usually credited to the Canadian Sir Sanford Fleming, who proposed dividing the world into 24 time zones, each consisting of 15 degrees; he proposed the idea to the International Meridian Conference, in 1884. The idea, however, preceded Fleming; in 1858, the Italian mathematician, Giuseppe Barilli, (writing under the pseudonym Quirico Filopanti) set out a system of 24 time zones divided along the meridians of latitude, with Rome as the prime meridian.
The whole notion of a standard time across a larger geographic area goes back even further, to the establishment of Railway Time in England. For most of the history of timekeeping, time meant local mean solar time, which varied from one location to the next, depending on longitude – the difference is about four minutes for every degree of longitude, which at the latitude of London is less than 70 miles. Without a standard time across the rail network, you can imagine the potential for horrendous accidents.
The idea of a clock showing the time in different time zones around the world is much older than any of us generally suspect – they were rare, but world time clocks were made as early as the early 17th century. Possibly the oldest known is a crucifix clock, made by the German clockmaker, Hans Neidtner, in 1630.
The modern history of world time watches begins at about the same time that time zones with one hour offsets from Greenwich Mean Time had become widely adopted, which was about 1929-1930. In 1931, the Genevan watchmaker Louis Cottier filed a patent for what we now recognize as the world time complication. The first world time complications based on Cottier’s patent had a 24 hour ring; the owner simply set the correct local time, accounting for AM or PM, and the time could be read off in all 24 full hour offset time zones. The hands turned clockwise while the 24 hour ring turned counterclockwise.
The first world time watch Cottier produced wasn’t for a watch brand; it was a pocket watch, created in 1931, for Baszanger, a jewelry retailer based in Carouge, a suburb of Geneva where Cottier had his workshop. In 1932, Cottier began producing world time watches for Vacheron Constantin, the first of which was the ref. 3372 pocket watch (there is an excellent disassembly article of this reference at The Naked Watchmaker, which despite showing signs of its age is terrific to look at if you want to get a sense of what the standard was for high end hand made watchmaking before World War II).
The city ring on the earliest Cottier wristwatches and pocket watches was fixed, and the position could only be changed by a watchmaker. This meant that if the owner were traveling to a different local time zone, the reference city couldn’t be changed, although local time in the new time zone could still be read reasonably easily – the hour hand would show the hour in the home time zone and the minute hand in combination with the rotating 24 hour ring, allowed the local time to be read. By 1937 Cottier had begun adding rotating city rings, which were turned manually to change the reference city at 12:00. These city rings were on rotating bezels, but were also placed on rings on the dial which could be rotated either by an outer turning bezel, or by a second crown.
Cottier began producing world time watches for Patek Philippe in 1937, and over the years, Patek world time wristwatches have been a vehicle for a wide range of designs and decorations. Some of the most beautiful Patek world time watches have cloisonné enamel, stylized maps of the Earth and continents at the center of the dial; these could be customized for particular markets and particular clients. Patek has also combined the world time complication with other complications, including a date which is coordinated with local time, a flyback chronograph, and even a minute repeater which, quite ingeniously, always chimes local time (that is, it will chime the correct time for whatever is chosen as the reference city and time zone).
Patek Philippe’s production of world timers in the 20th century ended in 1957, with the launch of the 2523-1, which was a variant of the ref. 2523, launched in 1953.
The Modern Traveler’s World Time Complication
The world time complication as we have come to know it today, uses a system designed to allow the local time shown by the hands, as well as the reference city and 24 hour disk, to all be reset to a new time zone simultaneously via a pusher in the case at 10:00. Press the pusher, and the hour hand advances in one hour increments; at the same time, the 24 hour ring advances by one hour, and the reference city at 12:00 also changes to reflect the change in time zones.
Surprisingly enough, as iconic as the system has become for Patek Philippe, it is a relatively recent addition to the world time complication – the first wristwatch to use this system, the ref. 5110, came out 24 years ago, in the year 2000. The impact of the launch of the 5110 was enormous – as Wei Koh points out in his history of the Patek world time complication, nobody at that point had seen a new world time watch in close to fifty years, and the update to the usability of the world time complication at long last, made the world timer a true world traveler’s watch for the jet age, combining the ease of use of a GMT watch with the comprehensiveness and visual poetry of the world time complication.
The movement had been updated as well – the 2523-1 used the hand-wound caliber 12”’400 HU (HU stands for “Heures Universelles”) but the new world time system used the automatic caliber 240 HU, built on the extra flat, microrotor caliber 240 first introduced in the Golden Ellipse in 1977.
There is little if anything to object to about the traditional Cottier world time complication, unless you happen to live, or are traveling to, one of the timezones that is not a full hour offset from GMT. A number of timezones have 30 minute or 45 minute offsets from GMT. Almost every world time watch ever made does not attempt to account for these offsets (one example is Nepal, which is GMT+5:45) and as they are designed to advance the hour hand in full hour increments, GMT watches can’t account for such timezones either.
There is, however, one company which took a shot at it – Vacheron Constantin, which launched its Traditionelle World Time watch in 2011, and then produced the same complication, but in the Overseas collection, in 2016.
In order to show the time in all 37 time zones, the watch adds a considerable degree of complexity to Cottier’s original complication. In a conventional world timer, it is not necessary to change the position of the minute hand if you change time zones, thanks to the full hour offset from GMT, and the hour hand always jumps in exactly one hour increments. If you want to have a 37 time zone world timer, not only do you have to add an additional 13 time zones, you also have to create a system of cams which can advance the hour hand, and the minute hand, in half hour or 45 minute jumps for the time zones that require it.
Despite the additional complexity, setting and using the Vacheron Traditionelle World Time is pretty straightforward. There’s no pusher; all setting is done via a couple of crown positions. Pulled out to the first position, the crown sets the local time, synchronized with the 24 hour ring (which, in another change from tradition, moves clockwise rather than counterclockwise around the dial).
The second position of the crown changes the reference city – which is at 6:00 on the dial, rather than 12:00, as is usually the case – and, as the reference city changes, the hour hand jumps ahead in either one hour, 30 minute, or 45 minute increments. Fascinatingly, the minute hand does as well – if for instance you set the reference city to Delhi, which is GMT+5:30, the minute hand will jump half an hour; the 24 hour disk follows along as well.
Of course, the Lord giveth and the Lord taketh away, as the saying goes, and while this is an incredible technical accomplishment, it presents a new set of problems. The basic issue is that time zones are not natural phenomena, although of course they depend on natural phenomena – the time zone or zones any given nation chooses to use are a matter of statute, not astronomy, and all it takes is one alteration of a chosen time zone by legal fiat, and your 37 time zone watch will require an update to the city disk (and, more expensively, possibly to the cam system under the dial as well).
This is of course, merely a more modern and somewhat more complicated version of a problem inherent to any world time watch. The names of cities change over the course of history, as do their chosen time zones. The classic example for Cottier type world time watches is the time zone for Paris. Before World War II, Paris and London shared the same time zone, but during the Occupation, Paris was switched over to Central European Time and after the end of hostilities, it never switched back.
These discrepancies, however, are part of the charm of collecting world time watches – they are technical marvels and sources of tremendous aesthetic pleasure, but they’re also snapshots of certain moments in history. It’s possible to see the inevitable obsolescence of city names and time zones as a fault, but to many collectors (and to me) those dials with outmoded time zones and city names are an intrinsic part of the charm of the world time complication as a whole – in other words, a feature, not a bug.
Featured in our story: The Vacheron Constantin Traditionelle World Time; the Patek Philippe ref. 5131P, in platinum, with cloisonné enamel dial and platinum bracelet. Watch Tim Mosso’s video review of the Vacheron; and also his review of the 5131. Excellent in-depth stories on the evolution of the world time complication at Patek Philippe can be found at Revolution, and from world-renowned Patek Philippe expert John Reardon, at Collectability.