Longines Spirit Zulu Time: A Vintage-Inspired Dual-Time Watch

The vintage-inspired GMT watch is now available in a new 39mm size, in four distinct colorways including one steel-and-gold version.

If you’re like many people who’ve seen the Longines Spirit Zulu Time watch since its initial launch in 2022, you’ve probably found yourself intrigued with its clean, legible dial, sleek-looking bezel, and meticulously finished case, even if you realized afterward that you really weren’t sure what “Zulu Time” was. Good news: we’re here to explain everything you might want to know about the Longines Spirit Zulu Time. Even more good news: if you liked the first crop of watches but found them too large for your taste, Longines is now supplementing the original 42mm offerings with new 39mm versions.  

First, some background. As those with a background in either the armed forces or aviation (or both) likely know, “Zulu” is the radio transmission articulation for the letter “Z” (like “Alpha” for A, “Tango” for T, etc.) and the letter “Z” is used in military jargon to denote time based on the prime meridian in Greenwich, England, the longitudinal line that separates the Eastern and Western Hemispheres. Essentially, Zulu Time means the same thing as GMT (Greenwich Mean Time) or the more modern term, UTC (Universal Time Coordinated, albeit expressed in a more historically adventurous idiom, and a watch that displayed the time in this manner was particularly useful for early aviators before the rise of electronic guidance systems. Thus it is fitting that Longines uses the term for the first dual-time model in its Spirit collection, a watch family that takes its inspiration primarily from aviation watches that the Swiss brand produced in the early 20th century, which were worn by pioneering pilots like Amy Johnson, Clyde Pangborn and Hugh Herndon. Also noteworthy is the proprietary movement that powers the watch’s timekeeping and GMT functions, which Longines introduced just last year in the first Spirit Zulu Time models.

Like many of Longines’ most popular models these days, not only in the Spirit line but also in the historically influenced Heritage collection, this one takes its cues — and in this instance, also its name — from a historical predecessor, the first Longines “Zulu Time” wristwatch, produced in 1925. In keeping with the Art Deco era in which it was released, that watch had an angular square case and ornate hour numerals, along with a third hand to indicate a second time zone and, most notably, a Zulu flag emblem with a red letter “Z.” 

Longines’ history in this style of timekeeping goes back even further, however, to a pocket watch developed in 1908 for clients in the Ottoman Empire (today known as the country of Turkey, or more recently, Türkiye), which had separate hands to display French time and Turkish time simultaneously, an innovation for which Longines filed a patent in 1911. The Swiss watchmaker continued to develop dual-time mechanisms throughout the 1930s and beyond, including the dashboard clock used by Herndon on his historic flight from the U.S.A. to Japan in 1931; this device had double hands for hours and minutes and two concentric 24-hour dials. Longines later partnered with naval officer and navigational tool inventor Philip Van Horn Weems on another dual-time watch, a collaboration that would lead to a subsequent team-up with Weems’ protegé, Charles Lindbergh, and the creation of perhaps Longines’ most renowned contribution to navigational timekeeping, the Lindbergh Hour Angle watch. It is this epoch of aviation innovation that informs the Spirit collection, and the Zulu Time model, with its pilot-friendly dual-time functionality, might be its most authentic expression yet. 

Longines unveiled the first Spirit Zulu Time models in 2022, all in stainless steel cases measuring 42mm in diameter and just shy of 14mm thick. In keeping with the ongoing, industry-wide push to downsize many larger models to a more widely wearable, unisex-friendly aesthetic, Longines has expanded the Spirit Zulu Time collection this year with the introduction of a new 39mm size, subtly but perceptibly slimmed down in profile to 13.5mm. Longines has also dipped its toe into the more luxurious end of the pond with this new generation, offering as its highlight piece a bimetal, two-tone model with a crown and bezel made of 18k yellow gold. Like their 42mm predecessors, the watches feature matte black, sandblasted anthracite, and sunray blue as the dial options, and use (on the all-steel models) blue, black and dark green for their ceramic GMT bezel inserts. New to the collection is the chocolate-brown bezel insert with gilt GMT track that adorns the steel-and-gold model. 

The Spirit Zulu Time’s round case won’t remind anyone of the historical 1925 watch that inspired it, but it does settle firmly within Longines’ Spirit collection, which in addition to the Zulu Time models comprises several three-hand date models —  including a titanium version introduced in 2021, one of the few non-steel options — as well as a handful of chronographs. The new watches’ 39mm cases boast an impressive level of finishing, with alternating brushed and polished surfaces that Longines executes more expertly than most at this price point. The cases’ 100-meter water resistance is secured by a screw-down crown, and their key visual and functional element, the bidirectional rotating bezel with color-coordinated ceramic insert, uses engraved and lacquered numerals for the 24-hour GMT scale and an inverted, luminous-coated triangle at the 12 o’clock/24-hour position.

The applied Arabic hour numerals and sword hour and minute hands, in either polished silvered or polished gold-tone, are coated with faux-vintage “Old Radium” Super-LumiNova for nighttime legibility. The watch is, enthusiasts should take note, a “true” GMT — meaning that the central GMT hand is adjustable independently of the hour hand, a technical rarity at this price level for a Swiss-made watch.The hand’s luminous-coated arrow tip — in blue, orange, or gilt-polished depending on the model — points to the wearer’s home or reference time on the bezel’s 24-hour scale. No, Longines doesn’t go so far in its historical references to resurrect the Zulu-flag “Z” on the dial, but those looking for additional historical touches will find one above the elegantly faceted date window at 6 o’clock: a row of five applied stars, now a hallmark of the Longines Spirit family, whose use hearkens back to Longines watches of old and denotes a “five star” movement of the highest precision and reliability.

The new movement that earns those five stars beats dutifully behind the elaborately engraved caseback of the Spirit Zulu Time, held by six screws and bearing the historic Longines winged hourglass logo (the oldest registered logo in the world, incidentally) superimposed over a globe meridian motif. Caliber L844.4 has been produced exclusively for Longines by ETA, the prolific Swiss movement manufacturer with which Longines shares a parent company, the Swatch Group. Based on the automatic ETA Caliber A31.L411, it oscillates at 25,200 vph, contains 21 jewels, and offers a power reserve of 72 hours, or three days. (For those counting, that’s an improvement over the 64 hours of the base caliber, possibly owing to this one’s use of a friction-resistant silicon balance spring.) In its most recent updates to the movement, Longines has made two other key components out of antimagnetic material, ensuring that the watch meets the ISO764 standard for resistance to magnetic fields from 600 to 800 gauss. Significantly, the movement is also certified by the Swiss testing agency COSC for chronometric performance, so those five stars are no mere boast. 

The Longines Spirit Zulu Time completes its look with a color-coordinated calf leather strap in blue, beige or brown (the steel-and-gold model’s brown strap is highlighted with cream-colored contrast stitching to echo the faux-aged details on the dial), or a three-link stainless steel bracelet. The straps have a folding steel buckle with a new micro-adjustment system, while the bracelet offers a push-piece-operated folding clasp; all options are designed to be easily interchangeable.