When talking about Rolex watches, it is obvious you will come across the three-letter term “GMT”. The Rolex GMT-Master is a mainstay lineup within the brand’s catalogue, and it was an ingenious creation from Rolex in the 1950s. You will explore the illustrious history behind the design and inception of this iconic series. However, the question is –
Have you ever wondered what “GMT” stands for? More significantly, what “GMT” actually signifies in respect to a watch’s function?
Well, you no longer have to wonder as you can explore everything regarding the three-letters “GMT” and its significance in Rolex watches as you continue reading below.
What do you mean by GMT?
Generally, the three letters “GMT” refers to Greenwich Mean Time. Many of you may know that Greenwich is a place located in South East London that comes with a rich maritime history. The International Meridian Conference, Washington D.C., chose Greenwich as the “prime meridian” in 1884. Interestingly, Sir George Airy established this meridian thirty-three years ago in 1851.
Forty-one delegates from twenty-five countries assembled at the conference and together agreed upon choosing one meridian officially. The main aim was to ease the global navigation systems. The Greenwich meridian plays a significant role in both navigation and time-tracking. How?
Different zones across the world display time considering how much behind or far ahead they are from Greenwich. For instance, Paris is typically an hour ahead of Greenwich. Thus, it is GMT+1. However, the question is that what does GMT has to do with the Rolex GMT-Master. Let’s explore it.
GMT and the Rolex GMT-Master
In the 1950s, pilots and cabin crews could see that they were spending substantial time in different timezones away from home. As a result, leading aviators were earnestly looking for a device that could track the time of more than one timezone.
Keeping the needs of Pan-Am crew members, Rolex designed and unleashed its first GMT wristwatch in 1955. The Rolex GMT-Master features a 24-hour bezel that displays a second timezone via an arrow-tipped, large hand on the dial. This hand, referred to as the GMT hand, completed one rotation every 24-hour.
The GMT hand moved at half the speed of a regular hour hand. However, keep in mind that there are substantial differences between GMT timepieces and dual-time watches. The dual-time models have one primary display to tell the home time and a secondary 12hours hand or a sub-register to show the second timezone.
However, GMT timepieces have only one dial, an added 24-hour GMT hand, usual hands, and a rotatable bezel to display two to three timezones.
Tracking Time of Multiple Zones
Some GMT calibres can display three timezones simultaneously. However, it is not possible for all models. The significant fact is that you can set the GMT (24-hour) hand independently of the usual hour hand. And this functionality was seen in the ever-first Rolex GMT-Master model. People could use this function when Rolex introduced the now-famous GMT-Master II models in the early 1980s.
Let’s take a quick look at the basic functionality of a standard timepiece that shows one location’s time. It has one single 12-hour dial with hour, minute and seconds hands. The hour hand makes two complete revolutions every 24-hour. Now:
A watchmaker adds a rotatable 24-hour scale and an additional 24-hour hand to the standard 12-hour scale on a watch, thereby showing two times. You can change the time that the GMT hand indicates by moving forward or backwards the rotating 24-hour bezel. In this way, a watch displays two times of different zones simultaneously.
However, the independent hour hand presents two new options. The first one is that you can move the hour hand while entering a new timezone without touching the bezel, the GMT hand and the minute hand. The 24-hour hand will display your home time, whereas the standard hour hand will read out the local time on the dial.
Secondly, you can move the GMT hand and adjust the bezel consecutively to show three timezones. However, without a fixed 24-hour scale around the dial’s edge, reading the time can become slightly complicated.
The Rolex GMT-Master
If you jot down the most coveted timepieces in the world today, the Rolex GMT-Master model would perhaps be in the top 10. Rolex GMT-Master and GMT-Master II watches have complemented the wrists of many icons and celebrities throughout history. Some of the most popular models in the GMT-Master series are the Pepsi (red-and-blue), the Batman (black-and-blue), the Coke (black-and-red) and the Root Beer (black-and-brown).
However, every Rolex GMT-Master watch provides the same overall aesthetic, no matter its colour profile. The GMT-Master and the GMT-Master II have one significant difference between them. The original Rolex GMT-Master can track the time of two different zones. On the contrary, Rolex equipped the GMT-Master II with an independently adjustable hour hand that shows a third timezone.
Moreover, with the 12-hour hand with jumping feature, you can change the timezones very convenient when travelling. This hand can be adjusted forward or backwards without hampering the watch’s precision.