By Steve Lundin
Hang out at any airport and you’ll hear time referred to using the 24-hour format. This
makes perfect sense because 24-hour time is the horological language of aviation, the military and any activity that requires precision and a universal reference point. While the wristwatch world primarily revolves around the easily mastered 12-hour clock, interesting 24-hour timepieces are available for the aficionado who wants to keep time the way the big boys do.
Twenty-four hour watches are unique: the movement rotates once per day, necessitating a dial divided into 24-day parts. The watch also functions as a compass and can used to determine a global position based on its relationship to Zulu time. Dials can be found with markers ranging from 0-23 or 1-24. To add to the confusion some watches feature a 12 marker at the top and some a 0; additionally watches can be found with dials split with colors reflecting day and night zones.
True 24-hour watches should not to be confused with GMT watches, which feature a third hand for tracking a second time zone. However, this GMT function sometimes appears in the 24-hour format, like those found on the Tutima FX UTC 24, the Ball Engineer Master II World Timer or the incredibly popular (among pilots) Citizen Nighthawk. Most, however, are based on an analog display of 24 markers around the dial; sub dials, slide rules and additional features are just icing on the cake.
Our familiar 12-hour clock has its lineage in ancient Egypt. The concept of breaking tthe day into halves, ante meridien (AM) and post meridien (PM) charts the course of sun as it tracks across the sky with the midday as the dividing point. While 24-hour clocks have been dated back to the 14th century, it’s thought that the 12-hour clock grew in popularity during the 15th and 16th centuries because they were less complicated and expensive to produce.
The more logical 24-hour clock divides the day into 24 segments, beginning at midnight. Time in this system runs from 00:00–24:00. This timekeeping is also called military time and relies on an established reference point for precision time tracking. And where does this reference point originate? Greenwich, England, hence Greenwich Mean Time, or GMT.
The link between 24-hour timekeeping and aviation is a long one, dating back to the start of the Second World War. Notably, Elgin-Hamilton developed an eight-day elapsed time clock with a 24-hour dial to meet a solicitation for a cockpit clock issued by the Navy’s Bureau of Aeronautics and the U.S. Air Corps.
Twenty-four-hour time was strictly an instrument panel tool in an airplane until Gallet introduced the MultiChron Navigator chronograph in 1943.
This wristwatch created the model for advanced, aviation multi-function watches. This highly collectible limited run watch was the world’s first wrist chronograph that simultaneously displayed both 12-hour and 24-hour time. The 24-hour function was actually located in the additional GMT hand. Other features included an additional winding crown for adjusting the second hand for split second synchronization.
Recognizing the need for 24-hour timekeeping capabilities in the cockpit, the government solicited watch manufacturing contractors to make a 24 hour military watch. The usual suspects, Elgin, Bulova and Hamilton, produced 24-hour versions of the famous A-11 and A-17 military watches, which were issued to airmen during the late Second World War and Korean conflict.
The post WWII boom in civilian aviation fueled a need for advanced aviation timepieces, with few options available beyond what the military had ordered. It was the Glycine Airman, introduced in 1953, that came to symbolize the quintessential 24-hour aviator’s watch and helped popularize the style and satisfy the flying public’s need for a timepiece that could be used as a true aviation tool.
The legendary Airman is currently in its 24th iteration, and a book, Glycine Airman - a 24 Hour Timeline of Flight, is available for those who absolutely, positively need to know everything about the history of this watch. The Airman is produced by the nearly 100-year-old Glycine at its factory in Bienne, Switzerland. Recently acquired by Altus Uhren Holding AG, Glycine’s new CEO Stephan Lack has publicly committed to continuity, indicating that the Airman will continue to be available for generations to come.
The Airman can be had with everything from quartz to an automatic movement and ranges in case size from 38 mm-53 mm with a wide variety of features and dial treatments. The classic is probably the Airman Base 22 with an ETA 2893-2 automatic movement with a purist model available featuring three hands and two timezones. The Airman saw service in Korea, Vietnam, and the Sandbox and can be found on the wrists of pilots around the world. It is the less expensive alternative to possibly the most renowned 24-hour watch in the world…
Thanks to decades of aggressive advertising, the space program and pure style, the Breitling Navitimer has become the watch most closely associated with aviation. The Breiting Navitimer Cosmonaute literally rocketed to fame when astronaut Scott Carpenter wore a specially developed 24-hour version of the Navitimer into space in 1962 on his Mercury 7 spaceflight. Carpenter had actually lobbied Breitling to make this watch because he was so impressed with the Navitimer slide rule watch, which featured an E6B flight computer. Carpenter felt that day and night were irrelevant in space and suggested marrying the slide rule function with a 24-hour movement; thus was born the Cosmonaute.
The Cosmonaute is still in production and is one of nine models that comprise the Navitimer line; today’s larger-cased Navitimer World also features a 24-hour movement. For purists, the now retro styled Cosmonaute is relatively the same watch it was in 1963: a flyback chronograph with a Breitling automatic mechanical movement, three subdials, bidirectional crown, push-down sapphire crystal and, of course, a slide rule.
In the late 1990s Swiss inventor Roland Keller produced a line of 24-hour aviation watches with a clean look that was distinguished by dials with a 12 marker at the top position, a 24 marker at the bottom and two color zones representing night and day. The company ceased production in 2004 and Yantars were only available on the secondary market…that is until Mitchell Feig, of the Florida-based OCEAN7 Watch Company, acquired the remaining stock of parts and began offering a limited number of NOS Yantars in 2011. OCEAN7’s own AirNautic line features several models that pay homage to the designs of Roland Keller.
OCEAN7’s AirNautic 24-hour watches are designed in the United States, handmade in Switzerland and many models are available with COSC-certified movements. AirNautics emulate Yantar in style, with some interesting new features, like the customized 6497 manual wind movement and Cold Carbon Hardened Steel Case found on the AirNautic AN-24M model. AirNautic’s AN-24T Submarine is similar to the Yantar Submarine 24 II, with the addition of a brighter dial and gaseous tritium light sources.
Oris has catered to the professional sports market for years and has many aviation models. The newest, the 24-hour Blue Eagle, marks the 40th anniversary of the Blue Eagles Helicopter Display Team. Limited to just 1,969 pieces, it is Oris’ first watch with a 24-hour display. It is a large, 45mm automatic watch with a second time zone, two-tone case and Oris’ distinctive Quick Lock security crown and vertical crown.
Fortis has been very active with the Russian space program; the Fortis Official Cosmonauts Chronograph was selected as part of the cosmonaut gear loadout at Star City, the Russian cosmonaut training center. Fortis offers the Flieger Automatic Limited Edition Black 24H as part of its extensive line of aviation and space watches. It is a PVD coated 40mm watch with a simple 24 hour black dial, Swiss automatic 2893 movement on a padded leather strap. Its simple, 1970’s era military look is reminiscent of the Tutima, Marathon or Heuer Bundeswehr style watches.
Do a search for 24-hour watches and you’ll turn up some interesting products from companies that don’t have large ad budgets or vast dealer distribution. These watches are typically budget priced and made with a build quality to last at least as long as a Timex! For military styling take a look at the H3 Tactical Stealth Mission 24-hour watch. H3 has been supplying the Swiss Army for years and the Tactical Stealth features a Swiss quartz movement and 24 tritium markers in a 42mm PVD case.
The Nordschleife 24-Hour offers more classic styling. Nordschleife is a German produced watch with a quartz movement from a company known for racing inspired timepieces. This simple watch is available online from various auto enthusiast websites.
No review of 24 hour watches would be complete without acknowledgement of the Russian watch manufacturing industry. Without delving into the minutia of this murky industry, which could fill a book, suffice to say Russians have been churning out 24-hour watches for several decades.
The most popular and visible Russian brands are Raketa, Vostok and, Poljot, although they may appear under different brand names in different parts of the world. Russian watches vary in price, quality and reliability, so it pays to research a specific model on user forums before acquiring one.
While many Russian companies have produced 24-hour watches, currently the most accessible watch is the Aviator 24-hour watch, which sports a black treatment and is powered by a Poljot 2623 Russian movement.
Thinking in terms of 12-hour time is actually counterintuitive to the realities of the world, but we’ve long divided the day into 12-hour portions. The joy of opening the Pandora’s Box of 24-hour time is an evolving pleasure. It imparts a global sense, particularly when the concept of a Zulu reference point is understood.
Although there are many fewer options for 24-hour timepieces than 12-hour timepieces, choices exist for most budgets. Do your research before selecting your timepiece, there’s no shortage of sites dedicated specifically to 24 hour watches…this may be your first step to actually becoming an aviator!