In a period of my adult, professional, life, I spent many days (and nights) on planes flying around the world. For many of those years, I kept track of time with a Rolex GMT-Master II watch that kept track of two or three time zones at once.
The secondary, 24-hour dial, usually displayed the Greenwich Mean Time (GMT) while the primary 12-hour dial displayed the time zone I as in at any particular time. The third zone display, when used, often showed the Eastern Standard (or daylight savings) time of my home base.
The Rolex was a good automatic watch to keep track of different time zones. The company designed the timepiece originally for Pan Am pilots but also became common for many of us who spent time at various places in divergent time zones.
I also had a Breitling chronograph that had a small GMT watch on the band that displayed the Universal Time Code (UTC). As with the Rolex, the watch had to be reset form time-to-time to keep it correct, to allow for differences between 30 and 32 day months and such.
But a warning from the U.S. State Department advised travelers that crime conditions in several companies (like the Philippines and the Mideast) had led to violent attacks on visitors wearing expensive watches. A friend at the Pentagon suggested I switch to a Citizens Eco-Drive “Atomic Time” watch.
The Citizen provided standard GMT reference, tracked 23 different time zones, was solar-powered and reset itself every night from radio feeds around the globe. It also knew the difference between 30 or 31 day months, Leap Year and switches to and from Daylight Savings Time. The damn thing knew wherever I as and changed the “local time” to that location, often while flying late at night.
I bought a Citizen Promaster Navihawk in 1995 and still have it. It keeps perfect time. I’ve never had to reset it at any time or at any place for the past 26 years. It also costs less than one-tenth of either the Rolex or the Breitling, but I find myself wearing it more than any expensive Swiss automatic because if is always accurate and never needs attention or correction.
I also have two Luminox Swiss quartz watches that provide GMT functions. Both are made mostly of carbon fiber, are ultralight in weight and super-tough.
Nowadays, more and more travelers depend on their smartphones to keep track of time zones. I still prefer a watch on my wrist, but no longer have much use for a multi-zone GMT timepiece, but still have and wear some because I like them.
I also two Bulova “precisionist” watches that feature a super-quartz movement that provides accuracy to just seconds a year. One is a remake of a Bulova that went to the moon on Apollo 15. The other is an analog chronograph that measures time down to one thousandth of a second.
If I’m late for anything, I can’t blame it on my watch.