Explaining the moonphase without a video can be a little tough (we’ll have that for you soon enough), but it’s relatively intuitive once it clicks. The balance wheel represents the sun and then there are three discs which represent the earth, sky, and moon. The earth rotates once every 24 hours and you can read the time in each location on the globe on the 24-hour scale around the edge of the movement plate. Simple enough. The sky and moon discs rotate in opposite directions once each lunar month (29 days, 12 hours, 44 minutes, 3 seconds) to show the current phase of the moon through the aperture in the sky disc. You can visualize the current alignment of the earth, moon, and sun easily by looking at the relative positions of the balance, earth disc, and moon display. It will be 1,058 years before this mechanism needs adjusting by just one day. Check out this video to get a better sense of exactly what we mean here: