La Montre Hermès had, undoubtedly, one of the coolest moon-phase complications we’ve seen in a watch in a long time. The French luxury brand is usually known for its playful complications – remember the GPHG-award-winning Le Temps Suspendu from 2011, which allowed users to literally suspend time on their watch dial? Hermès knows too well that if it has to make an impression among watch aficionados preoccupied with traditional watchmaking maisons, things have to done differently. And that’s exactly what Hermès has done with the new Arceau L’Heure de la Lune, a timepiece with an unusual timekeeping and moon-phase display.  

Two dial options for this stunning complication

The watch’s 43 mm white gold case frames a dial of either gray meteorite or blue aventurine, both inlaid with mother-of-pearl, and houses an all-new movement, Hermès Caliber H1837, outfitted with a proprietary, patent-pending module. Here’s how it works: the time and date are displayed separately on two satellite subdials, which float above two mother-of-pearl moons, one each for the northern and southern hemispheres. The southern lunar view is on the top of the dial at 12 o’clock, the northern view on the bottom at 6 o’clock, an unusual arrangement that allows the satellite subdials — in black on the meteorite dial, white on the aventurine — to rotate clockwise, covering and uncovering both lunar disks in tune with the actual phases of the moon, completing a sweep around the dial every 59 days.

The complication was developed by Jean-Francis Mojon

This cosmic complication was developed for Hermès by Jean-Francois Mojon, who has in the past collaborated with brands, including MB&F and Harry Winston. This horological hide-and-seek comes courtesy of the module, developed exclusively for Hermès, which consists of 117 polished and bead-blasted components and measures a slim 4.2 mm thick. The module incorporates seamlessly into the H1837 self-winding movement, whose high-horology decorations include a circular grained and snailed baseplate, satin-brushed bridges and a rotor engraved with the Hermès “H” pattern.

Pictured here is the aventurine blue dial

Decorative detail also abounds on the dial, whose signature sloping-font Arabic numerals are swept over by blued steel hands, and whose moon disks each feature a special surface decoration: the southern moon features a portrayal of the mythological winged horse Pegasus (horses, of course, being a frequent Hermès motif since its early days as a saddlemaker), inspired by the Pleine Lune (Full Moon) works of artist Dmitri Rybaltchenko; the northern moon boasts a transfer illustration depicting a realistic view of the lunar surface.

Can you spot Pegasus on the southern moon?

The watch’s white-gold Arceau case, a staple of Hermès watchmaking since its was designed in 1978 by Henri d’Origny, attaches via its hallmark stirrup-inspired lugs to a matte alligator strap (three guesses which fine leather purveyor provides it) in either “graphite gray” or “abyss blue”. The Hermès Arceau L’Heure de la Lune is limited to 100 pieces in each dial version, each priced at $25,500; Hermès says they will be available at retail in Spring of 2019.