Precisely ascribing a date or even a broader time span of months and years to horological inventions and innovations can be a difficult thing to do. There is little documentation that can prove beyond dispute which watchmaker in which city of Europe invented which fundamental part of the watch mechanism at what time. Indeed, one of the phrases that appears most commonly in any history of watchmaking is “simultaneously invented by both”.
For instance, credit for the invention of the balance spring in the mid 17th century is given to both Robert Hooke and Christiaan Huygens. Both men claimed credit at the time and the dispute has remained unsettled ever since. Meanwhile, the balance spring is at the heart of the every modern mechanical watch.
And so it is with watches that tell them time at two, or more, different places simultaneously. When did the first watchmaker decide to add that extra hand or an extra mechanism to his watch?
Most histories of watchmaking say that Charles-Félicien Tissot, founder of the Tissot brand, made and sold the first dual time zone pocket watch in 1853. The official Tissot history confirms this.
And this seems to make sense if you look at the history of time zones. The first official time zone in the world was established in Great Britain on 1 December 1847. Till then each city in the UK, and indeed in most of the world, had its own time based on local sunrise and sunset.
However, with the advent of widespread railway connectivity in Great Britain, local times became messy to handle for railway companies. While railways lines ran on London time, station masters in individual stations had to use company-issued tables to convert local times in each city to London time. By the middle of the 19th century, railway companies began to realize the merits of standardizing the times at all railway stations and synchronizing them to Greenwich Mean Time in London.
As the time at railway stations often served as a standard for the surrounding villages and towns, soon all of Great Britain began to move to GMT. According to one estimate, by 1855, 95% of Great Britain had shifted to GMT. It would still take another 25 years before Great Britain would declare GMT as the national time zone.
Rolex GMT-Master II
In fact, the first country to adopt a national time zone is believed to be New Zealand, where, in 1868, official time for the entire colony was set at 11-and-a-half hours ahead of GMT.
The concept of national time zones and standard time intervals began to proliferate all over the world through the latter half of the 19th century, propelled by railway and telecommunications links. In many countries, standard national times would remain an open issue till well into the 20th century. In India, for instance, a unified time would be adopted only in 1955.
In any case, the development of time zones and the pioneering pocket watch by Tissot signified a new challenge for watchmakers. Since watches were an essential accoutrement for travellers and navigators, manufacturers soon began to wonder how they could accommodate time zones into their devices.
The easiest way was to include two independent movements into the same watch, each capable of being set independently. This way, the wearer could set one watch to home time and the other to whichever time zone he was travelling to.
This early iteration can be seen not only in vintage timepieces but also in much more modern watches such as Jaeger Le-Coultre’s Reverso Duo line.
Breitling’s Transocean Chronograph Unitime
Another simple but timeless method of showing a second time zone is the GMT style of dial. Here, an additional hand, concentric with the regular minute and hour hands, shows the second time. In some models, the GMT hand works on twenty-four rotations and time is read off a 24-hour bezel. In other models, the GMT hand jumps in one-hour or 30-minutes increments when adjusted, making it easy to set. This year at BaselWorld, a number of brands launched superb GMT watches including Seiko and Omega.
The gold standard for GMT watches, however, is the Rolex GMT-Master II originally developed in 1955 for specific use by airline pilots. Later it became the official watch of many airlines. The association with Pan American World Airways would serve as inspiration for one of Rolex’s more memorable print advertisement campaigns.
This year at Basel, Rolex unveiled a further iteration of the second time zone display in the form of a 24-hour off-centre disc. Presented on the flagship new Sky-Dweller piece for 2012, the new display is perhaps the most unambiguous display possible, with the second time zone read off an indicator triangle.
For travellers who juggle time zones frequently, yet another refinement of display is the inner or outer ring labeled with the names of several cities. The simplest execution of this design is in this year’s new Breitling for Bentley GMT V8 piece.
First convert your home time to the 24-hour format. Now simply rotate the bezel to align the name of your home city (or corresponding time zone) with the corresponding converted time on the outer 24-hour markings on the dial. For example, if it is 3.00pm in Hong Kong right now, simply rotate the bezel till the label for Hong Kong is aligned with 15. Voila, the other cities are now all aligned with their respective current times on the 24-hour markings.
Breitling for Bentley GMT V8
A more sophisticated execution of this system is that made famous by Patek Philippe in the brand’s legendary World Time watches. In 1950, renowned watchmaker and world-time expert Louis Cottier designed the first dual-crown World Time for Patek Philippe. Five years later, the brand began selling the Reference 2525 based on Cottier’s original design.
Here one crown was used to set the time and another one was used to set two inner rings: one with city names and other with the 24-hour-cum-day-night indicator. Once set, the watch would then automatically update times across all the cities, requiring no further settings.
Other modern interpretations of this design include Vacheron Constantin’s critically acclaimed Patrimony Traditionnelle World Time that displays all 24 hourly and 12 half-hourly time zones on a single dial complete with disc and sapphire crystal day-night indicator.
The most striking execution of the city disc at BaselWorld this year was Breitling’s Transocean Chronograph Unitime that combines a world time function with a 1/4-second chronograph on a new, in-house B-05 calibre.
Astron GPS Solar
Step away from mechanical movements and into the digital realm, and suddenly you leap ahead in terms of not only accuracy but also automation.
Seiko unveiled the new Astron GPS Solar this year that combines a conventional second time zone sub-dial, at the six o’clock position, with a radical new way of automatically setting the time on the watch. The Astron GPS is capable of connecting to GPS satellites, much like a mobile phone, to first locate the watch on the planet, and then set the time on the watch based on the corresponding time zone.
In other words, the Astron will take care of both determining where you are and what the right time for that location should be. All you need to do is point it at the sky and press a button. And it does all this with a mechanism that runs on solar power.
Today, the discerning watch buyer can choose from a variety of world time and GMT watches—from the latest in Japanese technology to the finest refinement of ancient methods. Indeed, there is enough choice to buy one for every time zone.