How does a Rolex GMT work?

[TP321]

Is the 4th hand meant to be set to the "other" time zone? If so, thats not a very easy way of knowing the exact time.....I have an Oris Flight Timer which has a second time dial within the main time dial for depicting the other time zone, which makes it easier to read.

I am surw i am missing something with the rolex.....

[Rotaree]

The 4th hand is simply another hour hand for the other time zone - the minute and second hands read the same in both time zones.

[Riff Raff]

On the models since about 20 years ago, the 24 hour hand is set as your reference or home time zone.

The hour hand can be set back or forwards to the time zone you are in - it sets in 1 hour jumps. The date complication is linked to the hour hand.

[alanm_3]

I set my home timezone using the "proper" hour hand and use the green hand to point to the second timezone (as indicated on the bezel)

[a340driver]

Rotaree said:

The 4th hand is simply another hour hand for the other time zone - the minute and second hands read the same in both time zones.

Unless you're in India or any of these places http://www.timeanddate.com/time/time-zones-interesting.html

[TP321]

Rotaree said:

The 4th hand is simply another hour hand for the other time zone - the minute and second hands read the same in both time zones.

Ok so is the bezel fixed or does it move? And if it does move - why?

[andy_s]

TP321 said:

Ok so is the bezel fixed or does it move? And if it does move - why?

It moves, which gives you the ability to record three times; normal (hour hand), timezone 1 (24hr hand read against the normal watch dial but imagine it in 24hr scale) and second timezone (read the 24hr hand directly against the bezel).

[bobbybee]

alanm_3 said:

I set my home timezone using the "proper" hour hand and use the green hand to point to the second timezone (as indicated on the bezel)

So, using wrong then, and making it more difficult for you to adjust the hours when needed.
Each to their own i guess

[audidoody]

How do you record the 3rd time zone from the 24hr hand against the 12-hour watch dial markers? After an hour the 24-hour hand would only be halfway between two hour markers.

[Riff Raff]

audidoody said:

How do you record the 3rd time zone from the 24hr hand against the 12-hour watch dial markers? After an hour the 24-hour hand would only be halfway between two hour markers.

Excuse the crappy photo. The outer bezel has 24 hour markings. This is an Explorer - basically the same as a GMT, but the bezel is fixed.

[bobbybee]

audidoody said:

How do you record the 3rd time zone from the 24hr hand against the 12-hour watch dial markers? After an hour the 24-hour hand would only be halfway between two hour markers.

I found this on TRF, explains how-to, well sort of
It can read 2 at once (1 using the main hands, the other time zone using the 24hr green hand).

If you want to read a 3rd time-zone, you rotate the bezel by how many hours forwards or behind GMT, your 3rd time zone is.

Here's an example:
I am a TRF resident in the UK, so usually my hour hand is set to GMT, as is the green 24 hand of my most excellent timepiece, the GMT-IIc.

I travel to Egypt (+2 hrs GMT), so on the plane I advance the standard hour hand forwards by 2 hours. Now the main watch hands are showing me local (Egypt) time, whilst the green 24hr hand is still showing me the time back home in London. (Note - you read the green hand against the Bezel numbers, not the main watch face!).

Now suppose I want to know what local time it is in LA. I know that PST is 8hrs behind GMT. So I rotate the bezel 8 notches clock-wise. The green hand will then indicate to me what LA time is (read off the Bezel; not the watch face). The main hands of course will still be showing local (Egypt) time.


You cannot read 3 time-zones simultaneously, but the Bezel rotation does make it very quick to flip to a 3rd time-zone.

[audidoody]

bobbybee said:

You cannot read 3 time-zones simultaneously, but the Bezel rotation does make it very quick to flip to a 3rd time-zone.

Yep. That's what I thought.

Even the official Rolex advice is misleading. It suggests you can read a third zone simultaneously with the first and second. Which is impossible as the 24-hour hand moves at half the speed of the hour hand.

I would imagine this would be the same for the Explorer.

[TP321]

Thanks to every one for your input, it has helped me understand how this watch works. I am a little disappointed though that really you have to "work out" the 2nd time zone - you cant just glance at the watch and see it...In that respect my Oris Flight Timer solves this problem in a more straight forward way (there is a second dial inside the main dial showing you the 2nd time zone - hours and minutes).

[robsa]

No, you can tell the second time zone at a glance. It's the third you have to 'work out' by rotating the bezel.

[RichB]

On many pictures I see of GMTs the red pointed hand doesn't seem to be in the correct position e.g. in the picture (randomly taken from the web) the time is 2:08 so one would expect the red hand to be pointing just past the 4 or 5 digit not mid-way between. Is this just a badly adjusted watch or am I missing the point?

[outnumbered]

That's showing 10:08, and the GMT hand is at or just past 9:00 on the bezel, so it looks OK to me.

[andy_s]

RichB said:

On many pictures I see of GMTs the red pointed hand doesn't seem to be in the correct position e.g. in the picture (randomly taken from the web) the time is 2:08 so one would expect the red hand to be pointing just past the 4 or 5 digit not mid-way between. Is this just a badly adjusted watch or am I missing the point?

First time zone - normal hands - 10.08-ish
Second time zone - 'red' 24hr hand in relation to dial - 0908 ( 'am' ) - '4' = 0800; 5 = 1000, between the two is therefore 0900
Third time zone - 'red' 24hr hand in relation to bezel - at the moment 0908 (but turn the bezel so the 0400 is at 12 and it would be 13.08, i.e. +4hrs)

[RichB]

Ah right I understand (and yes sorry 10:08 excuse my senior moment) so the red hand rotates once every 24 hours not every 12. That was where I was going wrong.

[andy_s]

RichB said:

Ah right I understand (and yes sorry 10:08 excuse my senior moment) so the red hand rotates once every 24 hours not every 12. That was where I was going wrong.

That's it, and it's independently adjustable in relation to the main hour hand, in hour increments. In the early GMTs and the Explorer Mk 11 'Freccione' the hand was a '24'hr hand - so slaved to the regular hour hand so the second time zone was read from the adjustable bezel. For most GMTs the hand was independently setable, so you could either use as old or use as above.

Normally a 24hr hand is one that is slaved to the current hour hand (ie tells you whether it's am or pm).
A GMT hand is independently adjustable to a different time zone.

[Riff Raff]

andy_s said:

RichB said:

On many pictures I see of GMTs the red pointed hand doesn't seem to be in the correct position e.g. in the picture (randomly taken from the web) the time is 2:08 so one would expect the red hand to be pointing just past the 4 or 5 digit not mid-way between. Is this just a badly adjusted watch or am I missing the point?

First time zone - normal hands - 10.08-ish
Second time zone - 'red' 24hr hand in relation to dial - 0908 ( 'am' ) - '4' = 0800; 5 = 1000, between the two is therefore 0900
Third time zone - 'red' 24hr hand in relation to bezel - at the moment 0908 (but turn the bezel so the 0400 is at 12 and it would be 13.08, i.e. +4hrs)

You can't actually tell easily whether the normal hands are at 10.08 or 22.08. The only way to know for sure is to pull the crown out to the first position, and jump the hour hand through 12 to see if the date changes. If it was set at 22.08, and you wanted 10.08, you just wind the hour hand back 12 hours.

It's caught me out more than a few times when taking delivery of a new (to me) GMT or Explorer- having the date change at 12 midday is a bit of a head scratcher the first time it happens.....