One of the most useful and popular horological complications, GMT timepieces are ideal companions for individuals who transcend borders. With a history in making such watches, this year marks a significant milestone for Longines as it celebrates the centennial of its Zulu Time wristwatch from 1925 with the launch of the Spirit Zulu Time 1925. This modern reinterpretation blends archival details with contemporary watchmaking innovation, paying tribute to its pioneering predecessor while delivering an up-to-date design and 21st-century precision.

The Original Longines Zulu Time (1925)

Launched in 1925, the Longines Zulu Time was the brand’s first dual time zone wristwatch. Named after “Zulu Time” (the aviation and military term for Coordinated Universal Time, or UTC), it displayed two time zones simultaneously, meeting the needs of early 20th-century aviators. Building on Longines’ experience gained through developing a 1908 dual-time pocket watch for the Ottoman Empire, the 1925 Zulu Time addressed the demand for reliable time zone navigation in long-distance aviation.

The Longines Zulu Time was the first to display local time and a second time zone simultaneously on a single dial. Its name, derived from “Zulu Time” (UTC +0, the aviation and military standard), is symbolized by a nautical “Z” flag beneath the 12 o’clock marker. Encased in a 34mm × 24mm square 18K white gold case, the watch is powered by the hand-wound Longines calibre 10.68N

Unlike the round cases of modern Spirit models, the 1925 version featured a rectangular case, typical of the Deco era. A white gold example that sold at Antiquorum in 2010, combined luxury with utility, its dial displaying a Zulu flag and twin hour hands for local time and UTC. Powered by a hand-wound movement, it offered a 36-hour power reserve and likely used Arabic numerals for legibility, possibly with early luminescent material. The case was built for aviation’s rigors, though it lacked modern water resistance.

The Longines Spirit Zulu Time 1925: A Modern Tribute

The new Longines Spirit Zulu Time 1925 is housed in a 39mm stainless-steel case with a bidirectional rotating bezel equipped with a rose gold cap and a circular brushed insert. The reference represents an evolution of the 2022 Spirit Zulu Time, offering a more compact and elegant profile than its 42mm predecessor. 

The bezel is engraved with 24-hour graduations, which enables the wearer to track a third time zone. The rose gold cap is alloyed with copper, which is a subtle nod to the copper band embedded in the ground at the Royal Observatory in Greenwich. Placed there 350 years ago, it marks the Prime Meridian, which is the global reference for UTC. The engraved numerals and indices on the bezel add depth and interest. 

The matte black dial is complemented by rose gold-toned hands and indices, elements that are coated with Super-LumiNova, ensuring luminescent clarity in the lowest of lights. The dial is further punctuated with five stars above the 6 o’clock marker — a Longines hallmark denoting superior quality — and a discreet date window.

In a first for the Spirit collection, the Zulu Time 1925 features an exhibition caseback that gives a view of the movement and its rose gold PVD-coated rotor. This oscillating mass is engraved with a planisphere centered on the Prime Meridian. 

The Longines Spirit Zulu Time 1925 is powered by the L844.4 automatic movement with silicon balance spring. The caliber boasts exceptional resistance to magnetic fields, easily exceeding the ISO 764 parameter defining antimagnetic properties in wristwatches. COSC-certified, the movement delivers an accuracy of -4/+6 seconds per day and a power reserve of up to 72 hours.

The watch is offered with two interchangeable strap options: a stainless-steel bracelet with a double-fold safety clasp and fine adjustment or a black NATO-style strap with a pin buckle. Presented in a bespoke commemorative box, the Longines Spirit Zulu Time 1925 is also available with black or blue ceramic bezel inserts.

Tech Specs: Longines Spirit Zulu Time 1925 

Reference: L3.803.5.53.5
Movement: Self-winding COSC-certified Longines caliber L844.4; 72-hour power reserve
Functions: Hours and minutes; central seconds; second timezone; date
Case: 39mm × 13.5mm; stainless steel; bidirectional rotating bezel, insert with 5N 18K rose gold cap; 100-meter water-resistance
Dial: Matt black
Strap: Interchangeable stainless steel bracelet with double safety clasp; additional black NATO-style textile strap with pin buckle

Reference: L3.802.4.50.6 / L3.812.4.50.6 / L3.802.4.60.6 / L3.812.4.60.6
Movement: Self-winding COSC-certified Longines caliber L844.4; 72-hour power reserve
Functions: Hours and minutes; central seconds; second timezone; date
Case: 39mm × 13.5mm / 42mm × 14.10mm; stainless steel; bidirectional rotating bezel with two-tone ceramic insert (matt black or blue); 100-meter water-resistance
Dial: Matt black or sanded anthracite
Strap: Interchangeable stainless steel bracelet with double safety clasp