zOwie Omega Discussion Forum

I travel frequently and wanted a watch that could be easily set when changing time zones. At the same time, I wanted to know the time back home. Before I found out I needed a GMT watch and decided for the Omega Seamaster GMT, I looked at a variety of dual time watches. During the selection process, I learned about some practical aspects of the alternatives available in the market and would like to share that experience with you.

When we travel across time zones we need to move the hour hand of our watches forward or backward depending on the way we're heading. If I wear a regular watch, I have to move all hands of the watch in order to set the hour hand to the new local time. In some watches though, you can move the hour hand only, and not change the minute and second hands. A good example is the Perpetual Calendar line of Citizen EcoDrives. This is very convenient when you travel and also when Daylight Saving Time starts or ends. But if you also want to keep track of a second time zone, like your home time, then you need a GMT watch, with its extra hand. The GMT hand is a 24-hour hand that indicates a.m. and p.m. hours, so you can always tell whether it is day or night at home, no matter how far you are.

If you wear a good GMT watch, you can rapidly set the hour hand each time you move into a different time zone without changing the indication of minutes and seconds. And you can always tell local time the way you are used to, since it will be displayed by the regular hour, minute and second hands. At the same time, the 24-hour hand remains showing your home time. The date indicator, which is driven by the regular hour hand, will always change at midnight, local time, no matter where you are. That's super!

But beware: in many GMT watches, it's the GMT hand that can be independently set, instead of the regular hour hand. Believe me, it makes a BIG difference to the user. The fact is that many GMT watches are regular watches with the addition of a GMT module and its GMT hand. That GMT hand can be independently set, but the original movement and its basic functions remain unchanged. If you want to set the regular hour hand, you have to move the minute and second hands, just like a regular watch. This is a clumsy but low cost arrangement. It's adopted by the not-so-expensive ETA 2893-2 based watches but also by some expensive ones, like the Zenith Class Dual Time, just to mention a big name.

Fortunately, all Omega GMT models adopt the best arrangement, as do Rolex and Blancpain, among others. They allow for independent setting of the regular hour hand. And the date change is connected to the regular hour hand. Their operation was beautifully described by watch designer Francis Jacquerye about four years ago in an article that can still be found at http://fejack.net/misc/gmt24/gmt24.htm

Another arrangement, ingenious and very practical, is the one adopted by the less expensive Oris World Timer. It can be seen at the Oris site: http://www.oris-watch.com/english/index.htm . Instead of a GMT hand, the Oris World Timer has a sub-dial for the second time zone with hour and minute hands and a day/night indicator. And, of course, the main hour hand can be independently set.

I hope those of you who are in the process of selecting a dual time watch will find this information useful. At least two of my acquaintances got very disppointed when they first traveled with their new GMTs, simply because they made the wrong choices. I'll be happy if I can help to avoid further disappointment.