Focus on: What you need to know about the GMT Function

Focus on: What you need to know about the GMT Function
I’m sure you’ve all heard of the abbreviation GMT (Greenwich Mean Time) before, even if you aren’t experts in the world of watchmaking. I know this because most of you have taken a trip by plane at least once in your life, or figured out what time the last 2014 FIFA World Cup final match would be playing on TV… unless you live in Rio de Janeiro of course. Or if not, I’m betting that you’ve sent or received an email? I’m sure you’ve noticed the GMT or UTC (Coordinated Universal Time) printed in your email.
GMT is simply the longitude 0° determined by an international conference in 1884 in Washington D.C. so that a standard of time would be recognised by the world. Greenwich, England was declared as the “Mean Time” against which the rest of the Earth’s time zones would be compared. Beginning from the 1950’s, aviators traveling to other parts of the world, and literally crossing time zones in a matter of hours, would be able to keep their original time zone, set a local time to their timepieces with a 24-hour bezel and a second GMT hour hand. Needless to say, this came in quite handy for these constant travelers.
So how do you set such a function?
Let’s take for example, an iconic vintage, the Rolex GMT-Master reference 1675:

Step 1. Unscrew the crown and wind the watch if needed.
–
Step 2. Pull the crown all the way out in order to set the hour & minutes. The GMT hand will naturally follow. (Note: A number of purists will set the GMT hand to true Greenwich Mean Time as the official time reference, but this of course is entirely up to you).
–
Step 3. Now that the watch is set, screw the crown back in to place.
–
Step 4. By turning the rotating bezel, you can set the hour of the second time zone with the GMT hand as the point of reference. You’ll notice that on the scale of this particular model, nicknamed “Pepsi,” the blue refers to nighttime hours, and red for daylight, making it even easier to read the different times.
Originally made to accommodate the technical needs of aviators, the GMT function on a watch today integrates extremely well to the modern day traveler. Whether you travel for business or for pleasure, there’s no doubt that this user-friendly function will prove to be a true added value and advantage… especially if you don’t want to be burdened by additional watches.