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Thread: GMTs ???

  1. #1
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    GMTs ???

    Somewhere I'm not understanding the difference between types of GMT. What is a "true" GMT. What is not? I heard with some, the GMT hand can be "clicked" at one hour intervals. How does this work if you have a half hour time difference ie India is 5.5 hours ahead. What is the correct use of the GMT function? Which timezone would you set on which hands. Can anyone point me to some thread or article which gives the most basic understanding for dummies?

  2. #2
    Master Sinnlover's Avatar
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    Check out the you tube channel ’interesting watches’, he has a few reviews of GMTs and his latest video shows the difference quite well. (I have no connection but I have just watched his video)

    One type (eg Rolex) the hour hand can be adjusted independently of the minute and GMT hand allowing quick time zone changes this is something known as a traveller GMT the adjustment normally happens in hourly jumps.

    The other type (eg eta powered GMTs ) the GMT hand can be set independently in hourly adjustments. When you set the time the GMT moves at the same rate as the hour hand so this means you have to do a bit of fiddling to set the watch up when abroad - setting the time to local and than adjusting the GMT hand back to home time.

    In terms of half hours adjustments, it can’t be done on the either of these types of watch although I am sure there are some expensive versions out there that manage this.

    There is one other type of GMT that can manage half hour changes and that’s the type that is found in the flightmaster, it is independent of all hands and you can adjust it as you want, it shows time in the 12 hour format.

    With regard to use there is no correct way, you use it in the way that suits you.
    When abroad I normally set the GMT to London time and the hour hand to local.
    When in London I set the GMT hand to what ever time one I might be tracking.

    I hope this rambling helps
    Last edited by Sinnlover; 28th March 2021 at 16:39.

  3. #3
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    Mechanical GMTs aren't really good for handling half hour time differences, just whole hours.

    "True" GMT watches (or traveller) keeps the GMT hand on GMT or home time and you adjust the hour hand in hourly increments to your new location. The advantage of this is that the date is linked to the hour hand which means your watch tells you the correct time and date wherever you travel, whilst the 24-hour hand tracks GMT (or your home timezone if you want). The movement also allows you to move the hour hand in 1-hour jumps and doesn't hack the movement...ideal for timezone hopping.

    "Office" GMTs are pretty useless for travelling. The GMT hand is linked to the date and if you wanted the 12-hour hand to reflect your local location if you travel, the whole setting thing becomes a faff. People call them "office" because they say they work best if you don't travel and you are tracking someone elses timezone. Personally, I think they invented a situation that justifies an inferior design.

    Most cheaper GMTs tend to have the latter movement, usually ETA based...although in recent years there have been true GMTs appearing in mid-range brands.

    I think the first Rolex GMT-Master didn't have the independent hour hand so relies just on the rotating bezel as a GMT function whereas the GMT-Master II had the independent hour hand, so with the bezel you can effectively track three timezones.

  4. #4
    Master Qatar-wol's Avatar
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    (Someones' probably writing a better answer as I type, but) a traveller's GMT has an hour hand that can be stepped in one-hour intervals. Rolex GMT-II, Omega GMTs, many Seikos. My Landmaster.

    An office GMT is a simpler complication, and is, therefore, more common. The 24-hour hand can be moved by one-hour intervals. Sinn, anything with a 7750, etc.

    How's that?

    There are a few stealth traveller's watches - the 9F GS movement springs to mind - that allow you to change the local time without hacking the watch.

    Edit - ugh, beaten like a egg.

  5. #5
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    Youíll struggle for a sensibly priced mechanical that can do half hours properly. I settled for a mixed analogue and digital - digital telling the time in India and analogue the time here.

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    https://youtu.be/uTN7aPWbu3Q

    Skip to 4.14

    Sent from my SM-G935F using Tapatalk

  7. #7
    Master Christian's Avatar
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    Quote Originally Posted by RS404 View Post
    https://youtu.be/uTN7aPWbu3Q

    Skip to 4.14

    Sent from my SM-G935F using Tapatalk
    Spot on. My first GMT was a Rolex GMT2C and I assumed all GMTs worked this way. Not to knock TF, but when I bought a Speedbird GMT and discovered the "office" version I was extremely disappointed! It seemed the only purpose of that type of movement was to have a GMT hand and look like a proper GMT watch...actual useability was dreadful.

  8. #8
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    Thanks for the replies. Think I've got it now. The 2 places I normally travel to are the EU and India. For the EU, I don't really need a GMT. Just one hour difference. It's India where it would be useful with the 5.5 hour difference. But then from above, it would appear that is not an option. So I guess a GMT would not really be useful to me.

  9. #9
    Master DMC102's Avatar
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    Quote Originally Posted by Tiny View Post
    Thanks for the replies. Think I've got it now. The 2 places I normally travel to are the EU and India. For the EU, I don't really need a GMT. Just one hour difference. It's India where it would be useful with the 5.5 hour difference. But then from above, it would appear that is not an option. So I guess a GMT would not really be useful to me.
    A true GMT with a rotating bezel will allow you to set the local time on the 12-hour hand when in India, and to set the GMT hand to show UK time by stepping the bezel back or forward 30 minutes.

  10. #10
    Master Sinnlover's Avatar
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    Quote Originally Posted by Tiny View Post
    Thanks for the replies. Think I've got it now. The 2 places I normally travel to are the EU and India. For the EU, I don't really need a GMT. Just one hour difference. It's India where it would be useful with the 5.5 hour difference. But then from above, it would appear that is not an option. So I guess a GMT would not really be useful to me.
    A GMT that measures your home time on a bezel might work if it’s a friction or 120 click bezel.
    E.g. set the watch to local time, GMT to home but with the bezel off set to suit.
    A three handed watch with a 12 bezel would also work in the same way.
    Everyone needs an excuse to buy another watch.

    Edit DMC102 bear me to it.

  11. #11
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    Quote Originally Posted by Sinnlover View Post
    A GMT that measures your home time on a bezel might work if itís a friction or 120 click bezel.
    E.g. set the watch to local time, GMT to home but with the bezel off set to suit.
    A three handed watch with a 12 bezel would also work in the same way.
    Everyone needs an excuse to buy another watch.

    Edit DMC102 bear me to it.
    Yes. That's a solution. Thanks. The other alternative is to just wear 2 watches. A good excuse anyway.

  12. #12
    Grand Master MartynJC (UK)'s Avatar
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    Quote Originally Posted by DMC102 View Post
    A true GMT with a rotating bezel will allow you to set the local time on the 12-hour hand when in India, and to set the GMT hand to show UK time by stepping the bezel back or forward 30 minutes.
    Spot on.. These new fangled ceramic bezelled Rolex don't have 120 clicks just 60 clicks - so you would have to go vintage (steel) which have 120 clicks on the bezel. Or approximate the 1/2h which is close enough,

    I used to work in a multinational with world wide offices - so with a GMT watch - with the GMT set to my local office time (London) - just rotate the bezel forward 5.5h for India, and at noon when US wakes up - rotate bezel -6h (or -8h depending on office) for the USA TZ - read the remote time off the bezel. If I was travelling outside of GMT/BST I would set the local time using the jumping hour hand and still read times off the GMT hand - so actually had 3 timezones. Simples!

    Martyn

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  14. #14
    Master DMC102's Avatar
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    Quote Originally Posted by MartynJC (UK) View Post
    Spot on.. These new fangled ceramic bezelled Rolex don't have 120 clicks just 60 clicks - so you would have to go vintage (steel) which have 120 clicks on the bezel. Or approximate the 1/2h which is close enough...
    Or go Omega, for instance. My new-fangled Planet Ocean GMT has a 120-click ceramic bezel.

    Of course, even with 120 clicks, you're still approximating the 30 minutes on a 24-hour bezel scale. You'll always be an OCD-troubling six minutes out one way or the other.

    Still one of the best complications IMHO.

  15. #15
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    Quote Originally Posted by DMC102 View Post
    Or go Omega, for instance. My new-fangled Planet Ocean GMT has a 120-click ceramic bezel.

    Of course, even with 120 clicks, you're still approximating the 30 minutes on a 24-hour bezel scale. You'll always be an OCD-troubling six minutes out one way or the other.

    Still one of the best complications IMHO.
    What Iíve always thought would be great is something with an internal rotating bezel and an external click bezel - with one of the bezels as minutes and the other as hours. That way you wouldnít even need the gmt hand to get the half hour second time zone. Not aware of anything like that though.

  16. #16
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    Quote Originally Posted by Aggy View Post
    What Iíve always thought would be great is something with an internal rotating bezel and an external click bezel - with one of the bezels as minutes and the other as hours. That way you wouldnít even need the gmt hand to get the half hour second time zone. Not aware of anything like that though.
    Very good! I wonder why it hasn't been done. Or has it? Anyone??

  17. #17
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    No external bezel, two internal rotating bezels...

  18. #18
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    Quote Originally Posted by Nealywheelie View Post
    No external bezel, two internal rotating bezels...
    Like that - hadnít seen it. Like it on your strap more than the brown leather on their website. Olive green dial and Iíd have pulled the trigger already!

  19. #19
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    Thanks, & yeah the brown strap is absolute pants, ditched immediately. Mine is on the Staib mesh wish suits it beautifully IMHO.

  20. #20
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    Great. Are the bezels infinitely variable? What is the model number/name please? Do any other manufacturers do something similar?

  21. #21
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    OK. Found it. Bulova Pilot Watch A-15. Ref: 96A245. Are the bezels infinitely variable or do they have minute or hour click stops?

  22. #22
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    Quote Originally Posted by Tiny View Post
    OK. Found it. Bulova Pilot Watch A-15. Ref: 96A245. Are the bezels infinitely variable or do they have minute or hour click stops?
    Hi, infinitely variable, so no click stops. I have found no 'slippage' whilst wearing.

  23. #23
    Grand Master magirus's Avatar
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    Quote Originally Posted by Sinnlover View Post
    Check out the you tube channel íinteresting watchesí, he has a few reviews of GMTs and his latest video shows the difference quite well. (I have no connection but I have just watched his video)

    One type (eg Rolex) the hour hand can be adjusted independently of the minute and GMT hand allowing quick time zone changes this is something known as a traveller GMT the adjustment normally happens in hourly jumps.

    The other type (eg eta powered GMTs ) the GMT hand can be set independently in hourly adjustments. When you set the time the GMT moves at the same rate as the hour hand so this means you have to do a bit of fiddling to set the watch up when abroad - setting the time to local and than adjusting the GMT hand back to home time.

    In terms of half hours adjustments, it canít be done on the either of these types of watch although I am sure there are some expensive versions out there that manage this.

    There is one other type of GMT that can manage half hour changes and thatís the type that is found in the flightmaster, it is independent of all hands and you can adjust it as you want, it shows time in the 12 hour format.

    With regard to use there is no correct way, you use it in the way that suits you.
    When abroad I normally set the GMT to London time and the hour hand to local.
    When in London I set the GMT hand to what ever time one I might be tracking.

    I hope this rambling helps
    I just took my Voyager out of it's box. From wound down to powered up, time set, and GMT hand moved to a different time zone then back to UK time took less then a minute. Not at all fiddly, and I think either type works as well as the other, it's just a matter of familiarity. Now you've made me want to keep the Voyager on, and I only changed to my DC56 yesterday!

  24. #24
    Master Sinnlover's Avatar
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    Quote Originally Posted by magirus View Post
    I just took my Voyager out of it's box. From wound down to powered up, time set, and GMT hand moved to a different time zone then back to UK time took less then a minute. Not at all fiddly, and I think either type works as well as the other, it's just a matter of familiarity. Now you've made me want to keep the Voyager on, and I only changed to my DC56 yesterday!
    By fiddly I mean by comparison to the other type.
    I put my Fortis Ďofficeí GMT on this morning because of this thread...

  25. #25
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    The only function the A-15 doesn't fulfil is indicating if the second time zone is + or - which a GMT does with the 24h bezel and hand. I understand it wasn't built specifically for time zone monitoring, but for elapsed time in navigation. So it could be used for time zones but not with a 24h readout.

    I suppose the part hour time zone problem could be solved by adding a second minutes hand to a GMT. But such a design would have to stack 4 hands (5 if you have a seconds hand as well) as well as a means of adjustment.
    Last edited by Tiny; 29th March 2021 at 22:51.

  26. #26
    Master DMC102's Avatar
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    Just realised I have a watch that deals with the India time difference effortlessly.

    The Longines Conquest VHP GMT can be set to display any two time zones you want, using the bonkers flash setting app on your phone. This uses the camera flash to encode and send the home and travel time to the watch.

    Once set, you switch between home and travel time just by pressing in the Crown, causing the hands to whizz round to display the time you want. Whether you're displaying home or local time on the 12-hour hands, the time in the other zone is always displayed by the GMT hand.
    Last edited by DMC102; 30th March 2021 at 22:40.

  27. #27
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    Quote Originally Posted by DMC102 View Post
    Just realised I have a watch that deals with the India time difference effortlessly.

    The Longines Conquest VHP GMT can be set to display any two time zones you want, using the bonkers flash setting app on your phone. This uses the camera flash to encode and send the home and travel time to the watch.

    Once set, you switch between home and travel time just by pressing in the Crown, causing the hands to whizz round to display the time you want. Whether you're displaying home or local time on the 12-hour hands, the time in the other zone is always displayed by the GMT hand.
    That’s very cool. So you set it via your phone for, say, uk time and India time (5.5 ahead I believe) and then just literally click the crown to change time zone? Does it then stay linked to your phone (ie; if I then fly from the uk to New York does it automatically switch to alternating between New York and India time each time I click the crown)?
    edit: and does the gmt hand serve much purpose in that case other than a third time zone and / or quick glance time?)

  28. #28
    Grand Master oldoakknives's Avatar
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    Quote Originally Posted by DMC102 View Post
    Just realised I have a watch that deals with the India time difference effortlessly.

    The Longines Conquest VHP GMT can be set to display any two time zones you want, using the bonkers flash setting app on your phone. This uses the camera flash to encode and send the home and travel time to the watch.

    Once set, you switch between home and travel time just by pressing in the Crown, causing the hands to whizz round to display the time you want. Whether you're displaying home or local time on the 12-hour hands, the time in the other zone is always displayed by the GMT hand.
    First time I've heard about that watch. Interesting.
    ďThe more I learn about people, the more I like my dog.Ē

  29. #29
    Master DMC102's Avatar
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    Quote Originally Posted by Aggy View Post
    That’s very cool. So you set it via your phone for, say, uk time and India time (5.5 ahead I believe) and then just literally click the crown to change time zone? Does it then stay linked to your phone (ie; if I then fly from the uk to New York does it automatically switch to alternating between New York and India time each time I click the crown)?
    edit: and does the gmt hand serve much purpose in that case other than a third time zone and / or quick glance time?)
    No, there's not a continual link between watch and phone like a smartwatch. The pulses from the camera flash are read by the watch through the tiny window in the one of 12.

    You can only track two time zones, so in your example, on your flight to New York, you'd simply use the app to send NY time to the watch as the travel time. If you needed to track Indian time whilst in NY, you could set the home time to that zone, but you wouldn't then have UK time.

    The GMT hand always displays the time in the other zone, so when you switch back to home time, you can still see the time in the travel zone.

    The watch also has a perpetual calendar that won't need adjusting until 2400, and automatically adjusts for Daylight Saving Time.

    Last edited by DMC102; 31st March 2021 at 08:28.

  30. #30
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    Here's a video showing the time zone changes. I have the non-GMT perpetual calendar version and I think the GMT has the perpetual calendar too.

    https://www.youtube.com/watch?v=eQ2nC4ZZACA

    Cheers
    Rory

  31. #31
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    Looks like the solution for the unequal hour timezones. Also available in blue and black dial versions with either bracelet or strap, in 41mm or 43mm sizes.

  32. #32
    Master Sinnlover's Avatar
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    The Longines VHP looks to be the ideal watch for someone who travels a lot or works in multiple times zones, I presume the cost is reasonable as well.
    I am not sold on the design but the functionality is awesome and if it were to appear in a watch that appeals to my rather limited taste I would definitely consider it

  33. #33
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    Quote Originally Posted by Tiny View Post
    Looks like the solution for the unequal hour timezones. Also available in blue and black dial versions with either bracelet or strap, in 41mm or 43mm sizes.
    Iíve got the bracelet and one thing that is a little disappointing is some quite sharp edges, itís just missing a bit of quality sadly. I think it would work well on other strap options though.

    Cheers
    Rory


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  34. #34
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    Quote Originally Posted by Rory View Post
    Iíve got the bracelet and one thing that is a little disappointing is some quite sharp edges, itís just missing a bit of quality sadly. I think it would work well on other strap options though.

    Cheers
    Rory


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    Is yours the 41 or 43mm?

  35. #35
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    Mine is the 41mm. It looks like it's been discontinued (still available if you have a look around though) and replaced with one that has a ceramic bezel. The model number is L37164766.

    Cheers
    Rory

  36. #36
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    Quote Originally Posted by Rory View Post
    Mine is the 41mm. It looks like it's been discontinued (still available if you have a look around though) and replaced with one that has a ceramic bezel. The model number is L37164766.

    Cheers
    Rory
    Thanks. Iíve been eyeing up the (non-gmt) vhp for a while as my next purchase so youíve told me about this at a good time! Personally really like the look of these, a good everyday look, which for a gmt watch I think is a good idea - I tend to only take one watch with me when Iím travelling. Havenít seen one in the flesh so will check re your comments on quality, but the hydroconquest is one of my favourites in my collection so hopefully compares.

  37. #37
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    Note my model is the non-GMT, perpetual calendar.

    Cheers
    Rory


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  38. #38
    Master pacchi's Avatar
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    I like that very much....price is OK too
    whenever I (we) need a GMT again, that would be a strong contender

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