The Moon takes about 29.5 days to complete one full lunar cycle, also known as a synodic month. This cycle is the time from one New Moon to the next New Moon, during which the Moon goes through all its phases: New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter, and Waning Crescent
. Although the Moon completes an orbit around the Earth in approximately 27.3 days (called a sidereal month), the lunar phase cycle is longer because as the Moon orbits Earth, the Earth itself moves around the Sun. This means the Moon has to travel a bit further to reach the same phase alignment with the Sun and Earth, extending the cycle to about 29.5 days
. In summary:
- Lunar cycle (synodic month): ~29.5 days (29 days, 12 hours, 44 minutes on average)
- Moon's orbit around Earth (sidereal month): ~27.3 days
The 29.5-day period is the time it takes for the Moon to complete one full set of phases and is the basis for lunar calendars
