Find the current moon phase for any date. See illumination percentage, days into the lunar cycle, and a monthly calendar view of all moon phases.
The Moon goes through a complete cycle of phases approximately every 29.5 days (synodic month). This cycle is caused by the changing angles between the Earth, Moon, and Sun as the Moon orbits our planet.
The average time between new moons is 29.53 days. This is different from the Moon's orbital period (27.3 days) because Earth is also moving around the Sun.
The percentage of the Moon's visible surface that is lit by the Sun. It ranges from 0% at new moon to 100% at full moon.