We once used to embrace a 13-month calendar, and some cultures still follow this format. So why are they 12 months instead of 13?

Here is when you can see the full moon according to NASA's Sky Event Calendar: April 12 (Pink Moon) — 0:22 UTC (Apr 13), 8:22 pm EST — Micromoon (most distant of the year) Oct. 6 (Hunter's Moon) — ...

The Islamic calendar is governed by the movements of the moon, meaning that each month starts with a new lunar cycle, marked by the "birth" of a new crescent moon. As it is based on the lunar ...

The full moon ... months. They are also most visible when a full moon is surrounded by thin cirrus clouds. Here is when you ...