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?

The full moon, the period when the moon is at its largest and brightest, is merely one part of the lunar cycle, which is approximately one month in length. While the full moon can be seen globally ...

(For those of us in the Northern Hemisphere, the moon travels in a counterclockwise orbit.) Each of these primary moon phases marks a quarter of the lunar cycle and lasts only a moment. The ...