Moon Phase Watches

About

A moon phase shows where the moon is in its cycle. Behind a small window on the dial, a disc carrying two moons turns slowly, so the moon fills in over about two weeks, sits full, then slips back out of view. One full cycle takes about 29.5 days, the same as the moon outside. Patek Philippe pairs the moon phase with its annual calendars, its perpetual calendars and the Nautilus 5712. Vacheron Constantin builds it into the Overseas Perpetual Calendar Ultra-Thin and the Overseas Moon Phase Retrograde Date. Audemars Piguet uses an astronomical moon on the Royal Oak Perpetual Calendar. This page brings together the moon phase watches we have listed from all three. Want to compare a few moon phases side by side? Book a time to see them in New York → Frequently Asked Questions What does a moon phase complication show? It shows the phase of the moon: new, waxing, full and waning. A disc carrying two moons turns behind a window on the dial, making half a turn for each lunar cycle of about 29.5 days. When no moon shows in the window, it is a new moon. When one sits centered, it is full. How accurate is a moon phase watch? A conventional moon phase runs on a 59-tooth wheel, which treats the lunar cycle as exactly 29.5 days. The real cycle is about 29.53 days, so the display drifts by roughly one day every two and a half years. Precision and astronomical moon phases use different gearing and stay accurate far longer. How do you set a moon phase? Look up the date of the most recent full moon and count the days since. On many calendar watches the moon phase has its own corrector, a small pusher in the side of the case that you press with a stylus. Each press moves the display forward one day. Check the manual for the hours to avoid. What is the difference between an annual and perpetual calendar moon phase? The moon phase works the same way on both. The difference is the calendar next to it. An annual calendar knows the length of every month except February, so it wants one date