Moonphase Complications: Two Hemisphere Displays

quattro · 2025-11-22T18:25:14Z

Explore the intricate world of two-hemisphere moonphase watches with Arnold & Son, Hermès, and Omega. Discover unique designs and calibers.

quattro

WPS member · Horological Meandering forum

30 replies1068 views21 photos

Emmanuel, known as quattro on WatchProSite, presents a captivating exploration of two-hemisphere moonphase displays, a complication that showcases the moon's phases as seen from both the Northern and Southern Hemispheres. His original post meticulously details three distinct timepieces from Arnold & Son, Hermès, and Omega, each offering a unique horological interpretation of this astronomical function. This article delves into Emmanuel's selections and the community's further insights, highlighting the diverse approaches to this intricate complication.

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Here are three very different watches with a Two Hemisphere Moonphase Display, showing the phase of the moon as seen from both the northern and southern hemisphere.

Best, Emmanuel

A/ ARNOLD & SON HM Double Hemisphere Perpetual Moon, ref. 1GLAR.U03A.C122A

Case: 42 mm, red gold

Movement: manual winding Caliber A&S1512 with 90 hours of power reserve from twin spring barrels

credit: Hodinkee

B/ HERMÈS ARCEAU L'Heure De La Lune with 'Black Sahara' Meteorite Dial

Diameter: 43 mm white gold case

Dial Color: Black Sahara meteorite

Caliber: Hermès manufacture H1837 with exclusive module

credit: The 1916 Company

C/ OMEGA SPEEDMASTER MOONPHASE, ref. 304.30.43.52.06.001

43 x 13,61 x 48,60 mm steel case

Dial: galvanic grey-coated meteorite dial on a blue PVD-coated base

Caliber OMEGA 9914

credit: Monochrome

BONUS: Waning crescent Moon as seen from the Northern Hemisphere (left) and Southern Hemisphere (right)

credit: Nasa

Key Points from the Discussion

The IWC Portuguese Perpetual Calendar is another significant example of an astronomically accurate double moonphase watch, often considered a benchmark in this complication.
Beyond the featured models, both the Omega Speedmaster Moonphase and the Arnold & Son HM Double Hemisphere Perpetual Moon are available in additional material and coating variants, such as a black PVD-coated Speedmaster and a steel Arnold & Son.
The IWC Portuguese Perpetual Calendar, while impressive, is noted for its substantial size (44mm diameter and 16mm height), which can be a significant factor for wearability for many collectors.
The beauty of mechanical watchmaking is evident in how the same two-hemisphere moonphase complication can lead to such wildly different aesthetic and technical expressions across various brands.
While the world time complication focuses on longitudinal differences, the two-hemisphere moonphase complication uniquely addresses latitudinal variations in astronomical observation.
The Hermès Arceau L'Heure De La Lune, despite its innovative dial, could have benefited from a more elaborately engraved case back to enhance its overall collector appeal.

The Discussion

JMan

Nov 22, 2025

I like the design of the Hermes the best. Visually the most attractive. But the movement finishing leaves a bit to be desired at this price range?

quattro

Nov 22, 2025

Yes, I also think that the movement is not

on par with the rest of the watch, unfortunately. Best, Emmanuel

Modernahab

Nov 22, 2025

Too true!

I own tne Heure de la Lune, and in my opinion, Hermès would have done better to have used a nicely engraved case back.