The lunar calendar is a method of measuring time that follows the cycles of the Moon, specifically the various phases it goes through over an average 29.5-day period, known as a synodic month.

This year's next Full Moon will be the August Sturgeon Moon, which occurs at 3:55 a.m. on Saturday, Aug. 9, 2025.

Moon Astronomy Lesson: Learn more about moon phases, a waxing and waning crescent or gibbous moon and the lunar cycles of Earth’s moon each month at SPACE.com.