How to set up a moon phase with a corrector button
Short answer: Most mechanical moon phase watches have a small recessed button on the side of the case. Each press moves the moon by one day. Use a soft, blunt stylus and keep clear of the night window when the date is changing.
How real watches do it
| Omega Speedmaster Professional Moonphase (legacy, hand-wound) | Corrector D. Omega says never with the hands between 7 and 12 o'clock. |
|---|---|
| Jaeger-LeCoultre Master Ultra Thin Moon (calibre 925) | Corrector B at 8 o'clock. The JLC manual sets no time window. |
Set up moon phase on most watches: 4 steps
Crown positions are numbered 1 / 2, from pushed in to fully out; correctors: C (date), D (moon).
N is the number of whole days since the last full moon. The interactive guide works it out for your location and today's date, and shows the exact count.
- 1
Park the hands at 6:30
Correctors can be damaged while the date mechanism is engaged (usually late evening to early morning).
⚠️ Avoid 21:00–03:00 on the dial. The date and moon mechanism is engaged then. Move the hands out of that window first (for example to 6:30), or wait. - 2
Moon corrector to FULL
Use the supplied stylus or a wooden toothpick, never metal. Press until the full moon is centred.
🎯 Full moon centred - 3
Then N presses
One press = one day on standard 59-tooth discs.
- 4
Set the correct time
Crown out, set the time, push in.
New to moon phase windows? Read how to read a moon phase window and how often to reset it.