History of The GMT & Where Supersede Fits In

Greenwich Mean Time (GMT) was established to create a consistent, global standard of solar time, which fluctuates throughout the year. As seasons change, days get longer and shorter, but your watch maintains a constant (or mean) time to keep everyone on the same page. It’s called Greenwich Mean Time as “ground zero” is at the Royal Observatory in Greenwich, London, which represents 0 degrees longitude. This Greenwich meridian is a reference line that became the official prime meridian for maps in 1884. Ships navigating the open ocean, for example, relied on this standard. Today, GMT is often (and incorrectly) used to describe Coordinated Universal Time (UTC), which effectively replaced GMT as the world standard in 1972. Technically, GMT is now just a time zone (UTC+00:00) or mean solar time.

A fly over of the Greenwich Royal Observatory, National Maritime Museum and Old Royal Navy College.

24 Time Zones

For 100 years, the Greenwich meridian was the agreed upon mark for 0 degrees longitude before it was replaced in 1984 by the IERS Reference Meridian. It’s fairly arbitrary as both meridians are very close to each other, but travel either east or west of the meridian and there are a total of 24 standard time zones. Generally, time zones are contained within 15 degrees longitude (with some exceptions) and all are offsets from UTC, which again acts as ground zero that slices between the eastern and western hemispheres. Let’s make things even more complicated. Although there are 24 standard time zones, separated by single hours, there are technically 37 as some countries use half-hour and even quarter-hour zones. Oh, and then there’s Daylight Savings Time, but we’ll just stop here.

Air Travel and the Glycine Airman

Of course, world travel was around for hundreds of years before air travel, but commercial jet aircraft and GMT watches occurred at roughly the same time. The speed at which a traveler could go from one time zone to another was dramatically increased and it was important for jetsetters to track at least two time zones – home time and the local time at their destination. In the beginning, however, it was pilots that were targeted by watchmakers as they were the most frequent travelers of all. In 1953, Swiss watchmaker Glycine introduced the Airman, which was the first watch able to show two time zones simultaneously. It was initially intended for military use (at the request of the British), but soon became a favorite of pilots as well. It didn’t have a third central GMT hand, but simply a rotating 24-hour bezel that could be positioned with the hour hand for the second time zone. The dial had 24-hour time as well with noon at the traditional 6 o’clock position along with DAY and NIGHT on either side. A bit unconventional, but certainly effective. It was a big success for the brand and in 1965, a newer generation traveled to space with NASA astronaut Pete Conrad on the Gemini 5.

The old Glycine building just down the road from Horage HQ.

Rolex GMT-Master

Glycine got the ball rolling, but it was the Rolex GMT-Master in 1954 that both popularized and standardized GMT watches. Working in collaboration with Pan Am Airways, the GMT-Master ref. 6542 with an additional GMT hand and 24-hour bezel was issued to flight crews for international travel. You may know this watch by its James Bond nickname, Pussy Galore, as it was worn by Honor Blackman in 1964’s Goldfinger. Of course, James Bond and Rolex have a long history. Many improved models would follow until 1983, when the GMT-Master II ref. 16760 debuted (although production for the original GMT-Master continued until 1999). The two models looked nigh identical (the latter was a bit thicker), but the GMT-Master II could independently adjust the primary hour hand in one-hour increments without affecting the minute, seconds or GMT hands. A rotating 24-hour bezel allowed for the tracking of a third time zone as well. The Rolex GMT-Master collection quickly became a favorite of frequent travelers as the stylish sports watch was a jack of all trades with an unmatched cool factor. There’s a bit of debate as to which option is better – independently setting the primary hour hand like the GMT-Master II or independently setting the GMT hand. Rolex’s approach allows users to easily set the primary display to local time, although some prefer setting the GMT hand instead (if tracking a business or clients overseas, for example). A watch with a 24-hour internal rehaut (or flange) and rotating 24-hour bezel allows one to easily track three time zones as the GMT hand can do double duty.

Credit: Bob's Watches

GMT Master Ref: 1675 Credit: Monochrome Watches

Supersede GMT

Supersede comes with four complications baked in – there’s no separate module as with some other movements. The modular K2 micro-rotor caliber includes a power reserve indicator, date, day/night indicator and GMT. With all of this going on, the 39.5mm case is still under 10mm thick at 9.85mm (K2 is only 3.6mm). How does this compare to other popular models?

Supersede in Atoll blue Credit: @w.kenny_

The “gold standard” Rolex GMT-Master II is 40mm in diameter and significantly thicker at 12.2mm, and this is without a power reserve indicator and day/night indicator. It makes up for the latter with a rotating 24-hour day/night bezel, but it’s a less technical solution. Both watches are certified COSC chronometers with an accuracy of -4/+6 seconds per day and use 904L stainless steel. Supersede and the K2 have an anti-magnetic and wear resistant silicon escapement and hairspring, while the GMT-Master II caliber 3285 automatic (not a micro-rotor) uses a nickel-phosphorus alloy for the escapement. It’s anti-magnetic, but not as light and wear resistant as silicon.

Perpetual 3285 Credit: Bob's Watches

Supersede has a 72-hour power reserve, while the Rolex with two less complications has a 70-hour reserve. The GMT-Master II also retails for CHF 10,500 compared to Supersede’s retail price of CHF 6,500. Rolex models like the GMT-Master II are also notoriously difficult to purchase at retail prices. Here's an interesting note - Rolex, Glycine and Horage are all based in Biel/Bienne, which is truly the heart of Swiss watchmaking.

72 hours generated from the slim 3.6mm K2 micro-rotor

Let’s drop a level to Rolex’s sister brand, Tudor. The Black Bay GMT is a signature piece that features a 24-hour Pepsi bezel, central GMT hand and date. The automatic Caliber MT5652 (not a micro-rotor) is a COSC-certified chronometer like Supersede’s K2, but lacks the silicon escapement, however it it has a silicon hairspring. It’s an integrated movement with a 70-hour power reserve, again falling a bit behind the K2. The 41mm steel case is also 14.7mm thick, which is significantly heftier than Supersede’s 9.85mm and the Black Bay GMT lacks power reserve and day/night indicators. It’s well priced at USD 4,175, but is a standard automatic and has less features/complications than Supersede.

The 70 hour power reserve Tudor MT5652 at 6.5mm thick. Credit: SJX

A Saturated Market

Just about every major brand has GMT models, from Rolex, Panerai and Grand Seiko to Hamilton, Mido and Yema. Even micro-brands are pushing out competent models such as the Farer Lander IV and Baltic Aquascaphe GMT, but few can match the features, dimensions and overall specs of Supersede and the K2 micro-rotor. In fact, relatively few luxury GMT models have micro-rotor movements at all, while silicon escapements and hairsprings remain rare. Supersede is about CHF 1,000 less than the next Swiss micro-rotor watch, which doesn’t have a GMT complication (or power reserve indicator, etc.). Comparing our watch to other GMT models usually excludes the micro-rotor, so the price differences are even more significant.

Supersede on the streets of Taipei. Credit: @the_vintage_guy

Benefits of a Micro-Rotor

The micro-rotor design allows for a thinner movement and case, which is important for dressier occasions and long term comfort. All competitor models mentioned above are over 10mm thick, even without many of Supersede’s integrated complications. Other GMT micro-rotor watches do exist, albeit at very high prices. Examples like Parmigiani Fleurier’s Tonda PF GMT Rattrapante for CHF 26,000 has a micro-rotor and innovative, chronograph-like rattrapante function. This allows the GMT hand to superimpose with the local hour hand with the push of a button when not in use. Cool, niche and expensive, and although it’s otherwise a time-only piece (without even a seconds hand), the case is still over 10mm thick. Supersede is a tough watch to compare as it’s truly unique to the industry. There just aren’t direct competitors with a comparable design and feature set for such an attainable price.

Supersede is an all-terrain sports watch that’s perfect for frequent travelers that want to venture beyond the board room, whether to a hiking trail, on the water or a formal event. It’s refined yet rugged and features a current water resistance of 100 meters with 200 meters the stretch goal. If we hit the 200-meter mark, it would a great achievement. Whether traveling from Europe to North America or anywhere throughout our standard 24 hour time zones, Supersede is the perfect companion with an independently set GMT hand coupled to a day/night indicator. A 3-day power reserve will keep the lights on even if set down for an entire weekend, while the power reserve indicator will always let you know the state of the mainspring. GMT micro-rotor watches are already rare and the ones that do exist are pricey and often have less features. Supersede and the K2 micro-rotor movement are the result of painstaking development and engineering from a Swiss performance watchmaker.

Horage might be small and independent, but we’re striving for the creation of amazing things.

Erik Slaven