Centre the full moon in the window, then advance one click per day since the last full moon. The control can be a crown position, a pusher or a recessed corrector, so pick your watch or "By complication" above for pictures.
Quartz chronographs can usually be re-aligned with the crown pulled out and the pushers. Mechanical chronographs reset with internal cams and need a service if they're off.
Keep the hands out of the night window (often about 9 pm–3 am) while quick-setting. Park them at about 6:30, set the date, then set the time.
The panel above shows today's moon age, illumination and days since full moon. Open any moon phase guide to set your exact location.
Watch discs show the northern-hemisphere view. South of the equator the sky shows the same phase mirrored left-to-right.