Full Moon calendar 2026 in Billings, United States

Full Moon

The moon shows its full face to Earth once a month. Well, sort of. In fact, the same side of the moon always faces the planet, but part of it is in shadow. And, in reality most of the time the "full moon" is never perfectly full. Only when the moon, Earth and the sun are perfectly aligned is the moon 100 percent full, and that alignment produces a lunar eclipse. And sometimes — once in a blue moon — the moon is full twice in a month (or four times in a season, depending on which definition you prefer).