Citizen 8730 Instruction Manual page 11

<Viewing the moon phase>
The moon phase indicator does not display the exact shape of the moon. Use it as
a guide to estimate the moon phase.
New moon
Moon phase:
Day 0
(Spring tide)
* The indicator may differ depending on the model.
<To Set the Moon Phase Accurately>
The moon phase can be more accurately adjusted by adjusting on the day of the new
moon (when the moon indicator is completely hidden on the moon phase, day 0) or
full moon (when the moon indicator is straight up on the moon phase, day 15).
First quarter moon
Moon phase:
Approx. day 7
(Neap tide)
Full moon
Moon phase:
Approx. day 15
(Spring tide)
Last quarter
Moon phase:
Approx. day 22
(Neap tide)
11