Tonight, July 27th marks a total eclipse of the moon, and the longest lunar eclipse of the century. Seen in several countries across the world, this eclipse will witness the sun cast its shadow across the moon, giving it a reddish glow before it disappears from view altogether.
Eclipses bear a certain mystique and romanticism about them with endless theories, old-wives tales and astrological consequences. In much the same way, the Moon Phase complication is one of horlogerie’s most romantic and whimsical complications, while not necessarily its most practically useful. It hardly seems necessary for anyone in the modern world to know exactly what the phase of the moon is at a given time, and even if it was, a quick glance up at the night sky would answer the question just as effectively as a moon phase watch.
So, what does a moon phase do? Like the name suggests, this horological complication indicates the phase of the moon (waning, waxing, new, full) and visually traces the approximately 29.5 day long lunar cycle on the face of the watch.
Moon phase complications are seen on both men’s and women’s watches and take on many forms. They may exude subtle elegance or be more like the whimsical ‘mug in the moon’ style adopted by Stepan Sarpaneva, the innovative watchmaker who includes a likeness of his own face in the moon!
Simple moon phase displays may show an image of the moon traveling through an aperture on the dial, with the shape of the aperture allowing the phase of the moon to be indicated. Even these simple displays though, allow the watchmaker to add their own flair by appearing brightly coloured, cast in precious metals or even adorned with gemstones in some cases. The position of the moon phase aperture also varies, with 6 o’clock being a popular location.
Most moon phases require manual adjustment approximately every 3 years to re-synchronise the movement with the actual lunar cycle, but many watchmakers are now creating moon phase complications that remain precise for about 122 years without needing any adjustment at all! As with most things, there is a constant race towards the most accurate version of the moon phase.
The mechanics of a moon phase complication are in fact pretty complex and involve two moons moving on a rotating disc in a manner that allows the 29.5-day lunar cycle to be accurately indicated. Rather than go in to the specifics of how this works, we are best served admiring the whimsical beauty of this particular feature.
We at HOT are fans of all things pretty, and here is our round-up of some of this year’s best moon phase watches, ranging from the simple to the intensely complex. Tell us which one you like best!