Time in flight is a key variable, to calculate fuel duration and to maintain course. Looking at the clock, during flight the aviation pioneers performed complex calculations using pen and paper. It came natural, therefore, to think of putting instruments on the clock itself that would speed up these operations. The simplest, yet most tedious, was to calculate Greenwich Mean Time. Longines responded to this need as early as 1925, with the first wristwatch model featuring a second independent hour hand, thus indicating two time zones. This was the Longines Zulu Time.
Ten years later, in 1935, Longines produced a pilot's wristwatch that, with a modern system, made it possible to read two time zones while maintaining a single set of hour and minute hands. On the dial is a mobile disc with a second time scale, which can be rotated by an additional crown at 12 o'clock.
In the same years, the company started the production of genuine aviation instruments with two time zones, including cockpit clocks with dual hour and minute hands and a rotating bezel with a luminescent indicator to keep track of flight time or fuel consumption.
Some of these innovations were created thanks to the collaboration of flying professionals. Such as Philip Van Horn Weems, a US Navy officer and inventor of navigation instruments and systems, who worked with Longines between 1927 and 1936. Together they created the Second Setting Watch, which served to quickly synchronise the seconds with the radio time signal and became part of the equipment of the US Air Force and Navy.
This year, Longines is launching the new Zulu Time and resuming its long tradition of manufacturing watches with dual time indications. A history that began no less than 1908, with the pocket watches for the Ottoman Empire, which indicated Paris time and Turkish time. The 2022 Zulu Time is a GMT with an independent second hour hand and a bidirectional rotating 24-hour bezel.
