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Moonphase is on 30 day basis on all watches or not?
Should be 29.5 days
Per some article:
The lunar month is approximately 29.5 days, but this is only an approximate number. The length of any given lunar month can vary by several hours, depending on the positions of the Earth and the Moon in their orbits, but the current average length of a lunar month is 29 days, 12 hours, 44 minutes, and 2.8 seconds. A moonphase display therefore will show an approximately correct moonphase, and different watches will show what’s actually visible in the sky with varying degrees of precision.
The disk has 59 teeth on its edge and it’s advanced one tooth per day (59 divided by two is 29.5) so it makes one half turn per lunar month.