What is a moon phase?

A moon phase watch follows the lunar cycle of the moon over a 29.5-day lunar month. The moon is showcased on the dial of the watch and moves with time to reflect the current lunar cycle from full moon to new moon.

How do I use my moonphase watch? 

1.  Gently pull the crown to the final position until time stops (position III) 
2. Turn the crown until you reach the correct moon position. Be sure to match the position to accurate moon phase by using a lunar calendar. The moon disc moves very slowly by incrementally jumping every 24 hours (each date change).
3. As time function rotates on position III, the hands will move while setting moon phase. Once accurate moon phase is achieved, set the hour and minute hands back to the correct time.
4. Be sure to reset the date indicator to correct date, and return the crown to position I.