Moon phase watches
Did you know, that there are watches displaying the exact phase of the moon using a mechanical mechanism? Moon phases, although not very practical for every day use, are considered one of the most beautiful watch complications.
What is a moon phase?
A lunar cycle lasts for 29 days, 12 hours, 44 minutes and 2,8 seconds or approximately 29,53 days. The Romans used the lunar cycle and added or subtracted days which is why we don’t have 29,53-long months today. A moon phase watch is a great way to have this stellar calendar on your wrist. Depending on the mechanism and the gear ratio, a moon phase watch needs to be adjusted every two and a half years to keep it aligned with the moon. More sophisticated constructions allow for much higher precision up to thousands of years.
How to read a moon phase
The typical moon phase in a luxury wrist watch is a “bosom” moon phase. A disc with two moons rotates in an aperture which allows to view about half of the disc and always displaying one moon. As soon as the last crescent of the waning moon rotates underneath the dial, the first part of the waxing moon starts to rise on the opposite side of the aperture. The rest of the dial is usually decorated with stars and a dark blue background to depict the night sky.
Cheap moon phase watches
A very cheap moon phase watch is the Sea-Gull M308S which also features a large date complication. If you’re looking for a more “complete” calendar, have a look at the Emile Chouriet Lac Léman Complete Calendar. If you’re interested in a more interesting display of the lunar cycle you should check out the Emile Chouriet Voie Lactée Moon.