Continuing its tradition of creating watches that combine interesting mechanics with whimsical ideas, Hermès has released one of the coolest moonphase watches I’ve ever seen. The Hermes Arceau L’Heure De La Lune presents a pair of stationary mother-of-pearl moons with a complementary pair of floating lacquer dials floating over the top that rotate around the dial once every 59 days, covering and uncovering the moons to to indicate the current moon phase in both the southern and northern hemispheres at once. One of the floating dials shows the hours and minutes, while the other counts the date. Hermès has further amplified the dreamy effect by inverting the moons, with the the top one showing the southern hemisphere and the lower one the northern hemisphere. Finally, the moons show different designs, with the lower moon featuring a transfer of the luner surface on top and the upper moon baring a subtle pegasus motif by artist and designer Dimitri Rybaltchenko (a work he calls “Pleine Lune” or “Full Moon”). You have a choice of two executions, one with a meteorite dial and graduated grey lacquered discs and the other with an aventurine dial and white lacquered discs – both utilize the same 43mm white gold Arceau case. Each version is limited to 100 numbered pieces.

You’re probably wondering at this point how this unusual complication works. Inside is an Hermès caliber H1837 movement fitting with a module called the Hermes Arceau L’Heure De La Lune that was designed specifically to create this display. The module alone requires over 100 components and is 38mm across (which is the resulting “wingspan” of the rotating discs), and there is currently a patent pending for the mechanism. The Arceau L’Heure De La Lune debuted a little over a year ago at SIHH 2019 and was one of the stars of the show. It combines technical mastery with artistic flourish in a way that’s quintessentially Hermès, and this was one of those watches that people stopped to look at in the windows every time they passed the brand’s booth. I count myself among them. The Hermes Arceau L’Heure De La Lune watch uses an Hermès in-house movement as a base for an exclusive complication that has a pair of discs showing the hours/minutes and date that spin over a dial with two mother-of-pearl moons. The result is a dual moon phase indicator that shows both the northern and southern hemispheres at once. It playfully reverses the usual hierarchy of displays on a watch dial and does so extremely effectively.

This year, we’re getting five new versions of the Hermes Arceau L’Heure De La Lune. They’re technically identical to last year’s two pieces, measuring in at 43mm and utilizing the same movement and module, but with new dial options. First up are two blue-tinted models, one with a dial of Lapis Lazuli and one utilizing a hard stone called Blue Pearl. The other three are made of real meteorite, with Lunar meteorite, Black Sahara meteorite, and Martian meteorite on offer. Yeah, that’s right – you can wear a sliver of the Moon or Mars on your wrist, elevating this watch’s concept to the next level. Meteorite dials are not uncommon these days, but Lunar meteorites are much more scarce, and I definitely haven’t seen a Martian meteorite available on a watch before.

The Blue Pearl and Lapis Lazuli versions are additions to the main collection, while the meteorite dials are all limited editions. The Lunar and Black Sahara versions are limited to 36 pieces each, while the Martian version is limited to just two (yes, two!) pieces with price only available on request. The Hermes Arceau L’Heure De La Lune has quite a few fans at HODINKEE, including Stephen Pulvirent and myself, and if you spend a little time with the watch and have anything like a romantic streak, you will probably find it quite captivating as well. The moon-phase complication in any form always has a whiff of the whimsical and pleasantly otherworldly about it, and the version of the complication used by Hermès is no exception.