The Breitling Watch Source Forums

This may be a stupid question, but why do some watches have a second watch on it's bracelets?

It's a UTC module (Coordinated Universal Time), which keeps time for a second time zone, or possibly a third if the watch to which it is attached already has a GMT function. The modules are typically in 24 hour time, so one revolution of the hour hand equals 24 hours, rather than twelve.

It is a UTC (Universal Time Constant) module permanently set to GMT or Zulu time. It is normally a 24 hour dial (although some early Breitling UTC's were 12 hour dials), and is a quick reference for, say pilots, who navigate by Zulu or GMT no matter where they are in the world.

Some watches like the B-1 (now Airwolf) have a UTC facility as part of their options but for watches that don't a UTC module was an option. Some like them and some hate them. Me I had 5 watches all with UTC's at one point so no guessing which side of the fence I sit. In fact I have a spare UTC on a Fighter bracelet waiting for the time I get back into watches and buy another B-1.









Hope this helps.

_________________

Have
B-1 Black Dial+UTC
Emergency Black+UTC

HAD
B1Vulcan+UTC
B2 Black+UTC
C.A. M1-Team SEB in the Volvo Ocean Race+UTC
Emergency Ti -Yellow+UTC
Mission -Black
Old Navitimer -RAFAT

If they are permanently set to GMT, what's the crown for, and what do you do when the battery runs down?

What do you do when the battery runs down? Sorry is this for real??

....and the crown? Nice one Jackson, you nearly had me going

"Mente le palle" old boy

_________________

Have
B-1 Black Dial+UTC
Emergency Black+UTC

HAD
B1Vulcan+UTC
B2 Black+UTC
C.A. M1-Team SEB in the Volvo Ocean Race+UTC
Emergency Ti -Yellow+UTC
Mission -Black
Old Navitimer -RAFAT

I guess those are my silly questions. You said they were "permanently" set for GMT or Zulu time. Taken literally, that implies they can't be set for any other time zone. That got me to wondering, if they can't be adjusted for other time zones, why do they have crowns? Likewise, if they can't be adjusted, what do you do when the battery runs out? Perhaps I was taking you too literally. If they can be adjusted, then presumably they can be set to something other than GMT or Zulu time, which means they aren't actually permanently set for anything; it's at the option of the user. I was assuming the latter when I made my first post, above, but if that's wrong, I want to be clear about it.

You are correct Jackson, but possibly took me too literally, you could set the module to a different time zone. However, by the nature of what they are i.e. UTC's, the Universal Time Constant or as you correctly called it Co-ordinated Universal Time, whch replaced Greenwich Mean Time (GMT) as the World time standard they would be "permanently" set to Zulu time, thus allowing the main watch head to be changed to local time. As I recall 48 atomic clocks world wide send their times to a central point (I believe in France) where the UTC time is calculated. Greenwich Mean Time (GMT) remains the standard time zone and Flight Mangement Computers and Air Traffic Controlers still refer to Zulu (GMT) for flight navigation purposes world wide.

Given though that a pilot would have it set "permanently" on GMT, one would still need the crown to adjust the UTC should it go slightly off time and of course, re-setting the time when that pesky battery was replaced.

_________________

Have
B-1 Black Dial+UTC
Emergency Black+UTC

HAD
B1Vulcan+UTC
B2 Black+UTC
C.A. M1-Team SEB in the Volvo Ocean Race+UTC
Emergency Ti -Yellow+UTC
Mission -Black
Old Navitimer -RAFAT

Sure, that makes sense. And duh...if Breitling had invented a watch that keeps perfect time and never needs to be adjusted, surely I would have heard of such a thing. Guess I should have thought of that before I asked.

I remember when I first heard of a GMT function, I thought, "Why do they call it a GMT function, if I can set it for any time zone I want? What if I don't want to set it for Greenwich Mean Time?" These days, I don't even think about it: to me, a GMT function is just a second time zone function, which can be set at the option of the user for any time zone. That tends to be how I think of a UTC module, too, although I can see why pilots would want to set it for GMT or Zulu and just leave it there. That would be a very useful feature to have on a watch.

Cheers.

Not a fan myself but now I understand this, I like the idea of it.