A question that periodically arises when we cover multi-time-zone watches is, what is it that really sets one apart from the other? There are a number of different solutions to the problems of showing the time in more than one time zone and, while some of them resemble each other superficially, each has its own advantages and disadvantages, and each offers its own unique take on showing you what time it is both where you are and where you are not.
The multi-time-zone watch is an interesting complication – unlike many other complications, such as the moon-phase and equation of time, and even the perpetual calendar, it is not based on recurring natural events, but rather on an invented convention, which is the division of the world into time zones. Each time zone follows a standard mean time across the entire time zone; prior to the development of standard times, the time was simply the local solar mean time. This meant, of course, that every town and village separated by longitude had a slightly different time, which didn’t matter very much at all until the invention of the railroad – the first standard time was so-called Railway Time, which was adopted in 1840 by the Great Western Railway in the UK. This time standard used GMT across the entire rail network. In 1879, Scottish-born Canadian engineer Sir Sanford Fleming proposed the division of the world into 24 standard time zones, and by 1900, most countries had adopted some form of standard time, which gradually evolved into the system we know today.
The recognition that time is different depending on where you are on Earth is not a new one. I remember being quite surprised to see, in an Antiquorum catalog for a sale of renaissance clocks which took place many years ago, a spectacular table clock which actually incorporated what looked for all the world like a modern world-time dial, complete with the names of different locations around the world (and which, to my considerable frustration, I have been unable to locate online; it’s a remarkable piece of evidence, if any further were needed, that really original ideas in horology are few and far between). However, the time-zone system is entirely modern and very much the consequence of the evolution of travel technology.
The Two-Time-Zone Watch With Independently Set 24-Hour Hand
This is probably the most common implementation of a multi-time-zone watch, thanks to the widely used ETA 2893-2, which offers a two-time-zone function, and its Sellita clone, the SW330-1. Both of these movements have an independently set 24-hour hand and date, as well as hour and minute hands for local time. A couple of years ago, James Stacey referred to this particular implementation of a dual-time-zone watch as a “caller,” which gave me a moment of dejection – I’m one of the older writers at HODINKEE, and I felt I had somehow missed a piece of au courant horological vernacular that was all the rage of the younger set (“I grow old, I grow old, I shall wear the bottoms of my trousers rolled, what the hell’s a caller?”) but as it turns out, the term is apt as we will see in a minute.
Local time is read off in the usual fashion, and the second time-zone is read off the 24-hour hand, which makes one revolution per day. Setting up the watch is pretty straightforward. You set the local mean time in the usual fashion by pulling the crown out to its second position. In the first position, the 24-hour hand can be set forward in one-hour increments by turning the crown clockwise, and the date can be quick-set by turning the crown counterclockwise. Date switching is driven by the local time display, not the 24-hour hand.
If you’re traveling from New York to Geneva (today, as I write, the time difference is six hours, with Geneva ahead), when you land at GVA, you have two choices. You can re-set the 24-hour hand to Geneva time and leave the hour and minute hand as they were, showing the time in New York. This, however, means the time display for the whole time you’re in Geneva will be a bit counter-intuitive to read – you’ll be reading the hour in Geneva off the 24-hour hand, and moreover, the date will not switch over at midnight Geneva time, but rather, six hours too late, because it will change over at midnight in New York. The other option is to re-set the local time to Geneva time, correct the date if necessary, and then re-set the 24-hour hand to the correct hour for New York. This is a bit less convenient than having a watch with an independently set local time hour hand, which you find on watches like the GMT-Master II, and it’s the reason James coined the term “caller” for such watches – they work better if you’re wondering what time it is at a place you call frequently from home. “Caller” watches can work just fine for travel, but since you have to reset the local time display and the 24-hour hand, and possibly the date, they’re a little less convenient than the next type of two-time-zone watch: what James likes to call the “flyer.”
The Two-Time-Zone Watch With Independently Set Hour Hand
This type of two-time-zone watch (or three-time-zone, if it has a turning 24-hour bezel) is what is sometimes called a “true” GMT watch, although the term “true” implies that all other implementations are false, which seems oddly judgmental. In any case, such watches are sometimes said to be more convenient for travelers than for stay-at-homes wondering what time it is elsewhere in the world – the “flyer” counterpart to the “caller” two-time-zone watches. The classic example is, of course, the watch that put “GMT” into the name of multi-time-zone watches: the Rolex GMT-Master and GMT-Master II (for all you could ever want to know about those watches, John Bues’ Reference Points is highly recommended).
Setting up such watches is straightforward. You pull out the crown to the third position; in this position, moving the crown changes the position of both the local time hands and the 24-hour hand. Set the 24-hour hand to the correct position for your local (home) time. Then, push the crown in slightly to the second position and set the date – date switching is via the local time hour hand, so you turn the hour hand forwards or backwards until you reach the current date. You then set the local time hour hand to the same hour as the 24-hour hand, and you’re done. Both the 24-hour hand and the 12-hour hand now show the same hour – the time at your current, or home, locale.
If you’re flying from New York to Geneva, once you land, all you have to do is pull out the crown all the way and set the local time hour hand forward to the time in Geneva. Since the date is indexed by the local time hour hand, as long as you remember to set the hour hand forwards instead of backwards (again, Geneva is six hours ahead), the date will automatically update to the correct date for Geneva. The 24-hour hand will continue to show home time. As you can see, this is very convenient for frequent flyers, who will want to easily set their watch to local time without stopping the entire watch or performing several different setting maneuvers. “Flyers” as opposed to the caller-type watches, for obvious reasons.
The “It Looks Like A World-Timer But It’s A Two-Time-Zone Watch” Wristwatch
These are kind of a variation on the so-called “flyer” GMT watches. Essentially, they’re two-time-zone watches, but with the addition of a city ring which resembles the city ring found on true world-time wristwatches. An excellent and very hifalutin’ example is the Lange 1 Time Zone; another is the Jaeger-LeCoultre Master Control Geographic.
As you can see, both of these watches might at a casual glance be mistaken for a world-time complication – the distinctive city ring is usually a dead giveaway that you’re looking at a world-time wristwatch. However, in both these cases, the city ring is there to provide a reference for setting the local time if you have just landed at your destination.
In both instances, you have the main dial, which shows home time, and a smaller dial that shows the time in a second time-zone, along with an AM/PM indicator. Both watches have a separate corrector for the smaller dial as well as correctors for the date (in the case of the Lange, in the form of a pusher at 7-8:00, and in the Jaeger, a corrector at 2:00).
Let’s take our hypothetical little hop to Geneva. When we land, setting the time on the smaller, second time-zone dial is a matter of just pushing (the Lange) or turning (the Jaeger) the corrector at 10:00. This causes the city ring to turn, changing the reference city on the city ring, and at the same time, advancing the hour hand of the smaller dial by one-second jumps. In the case of our trip to Geneva from New York, if we’ve set the watch up correctly, both dials show the same time, and the city ring pointer is at New York. When we land in Geneva, we just push the corrector until it points to Berlin (the Lange) or Paris (the Jaeger), and the hour hand in the smaller dial will advance to the right hour as the city disk turns.
It is a very attractive and practical system, with just a couple of drawbacks. The first is that the date is synchronized with the larger time display, so while you can see the correct time in Geneva, the date shown will be for New York. The second drawback is that one instinctively tends to perceive the larger dial as local time, rather than home time – this is really a matter of just adjusting to reading the watch differently, although I can certainly envision without too much trouble situations where an evening’s genteel carousing (for instance) might cause one to read the time off the wrong dial – and hilarity ensues, or maybe not. Purely from a legibility standpoint, this system seems to suffer a bit in comparison to simpler two-time-zone watches like the GMT-Master II, although what the mechanism loses in straightforward operation, it perhaps gains back a bit in elegance and pleasure of operation.
There are a number of variations on this system. The NOMOS Zurich Weltzeit is an interesting example, by the way, of a watch with a full city ring, but which functionally is closer to the GMT-Master II. Home time is shown on a small, rotating hours circle at 3:00, and advancing the city ring actually advances the main dial’s hour hand in one-hour increments. The problem of keeping the date coordinated is solved by the simple expedient of not having one.
The Aristocratic World Timer
Interestingly enough, the first wristwatch to show the time in more than one time zone is (as far as I know) the world-time wristwatch. The classic example is from Patek Philippe.
The world-time complication was developed by Louis Cottier and first used in pocket watches, by Patek, in the 1930s. A world-time watch is – well, just what it says on the tin, as the saying goes; it shows the time in all 24 time zones with full-hour offsets from GMT, simultaneously. This is thanks to a moveable cities disk with 24 reference cities on it, and a constantly driven hour disk, which rotates once every 24 hours. To set up the watch, you just press the pusher at 10:00 until your home city is at the top of the dial, and then set the correct time at the crown. If you want to know what time it is in any of the other 23 time zones, all you have to do is look at which number on the hour disk is adjacent to the city in question. If you happen to fly – let’s say, from New York to Geneva – all you have to do to show the correct local time is press the pusher until Paris is at the top of the dial. The hour hand will advance in one-hour jumps automatically to the correct local time, while the time in New York – and anywhere else, for that matter – can still be read off the city ring and hour ring.
The system has a lot going for it. It is sipping-tea-with-your-pinky-out elegant, and it is simple, practical, and enjoyable to use. Historically the one mark against it has been its higher complexity and higher cost, however, as with most other complications, it is now possible to find a true world-time complication in a more affordable timepiece as well (a Patek ref. 5230R, without that sexy cloisonné enamel world map, will set you back $ 48,540 smackeroos, but c’mon, that enamel world map – I want it, you want it, we all want it).
The only downside I can see to a world-time watch as a travel companion is that it’s not quite as instantly legible, in terms of reading off home and local time specifically, as a “flyer” GMT watch. However, what you lose in clarity, as is so often the case, you gain back in baroque old-world charm.
This watch and the world-time complication, in general, don’t say “kick the tires and light the fires” so much as they say, “Gadzooks! I must hurry to catch the noon Pan Am Clipper Flying Boat to Tahiti! (or wherever).” But that, to me, is a feature, not a bug. It goes without saying that the romance of travel, even when we could all travel enough to keep our miles topped up, has not been romantic in a long time, and even Business Class feels more like wandering through a gated community than sharing the joy of air travel with like-minded adventurers. Anything that can make the idea of travel seem what it used to be – a gateway to real adventure and, hopefully, to exotic locales and unexpected meetings – is a good thing in my book. I guess what I’m saying is that if the GMT-Master II has my head, the Patek World Timer has my heart. If I were still going to Geneva every time I turned around, I’d prefer a “flyer” GMT watch just to keep my jet-lagged head screwed on straight, but if I decided to go home the long way – around the world – I’d take the watch that puts the world on my wrist.