GMT

Presented in 2011, the GMT is the first Greubel Forsey watch to center not on an invention devoted solely to the tourbillon, but on a travel complication: a second time zone. The brand, already established for its tilted tourbillons, chose to apply the same technical rigor to a function more immediately useful in daily life, without abandoning its own mechanical language: the caliber still houses a 24-second tourbillon tilted at 25 degrees, faster than the traditional 60-second tourbillon and likewise designed to better average out the effect of gravity on accuracy.

The line's most recognizable element, however, is the small three-dimensional globe mounted on the dial, which indicates the reference time zone by genuinely rotating on its own axis once every 24 hours, with the world's major cities engraved on its surface: local time remains readable on the main dial, while a dedicated counter shows home time, adjustable via a pusher at 10 o'clock in one-hour increments. The combination of immediate legibility and hidden complexity made the GMT one of the most celebrated watches in the catalog, to the point of also receiving an award at the International Chronometry Competition in 2011.

In the years that followed, the GMT family expanded with new executions: the GMT Earth, with an even more detailed globe in titanium and gold; the GMT Sport, a version with a more contemporary design and a more modern case built for everyday wear; the GMT Quadruple Tourbillon of 2019, which combines the second-time-zone indication with the four tourbillon cages of the Quadruple Tourbillon line; and, more recently, the GMT Balancier Convexe, a more compact version built around a balance wheel rather than a tourbillon.