A lunar month is the period it takes for the Moon to complete one full cycle of its phases, from one new moon to the next new moon. This duration is approximately 29.5 days, also known as the synodic month. During this time, the Moon goes through its phases: new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, and waning crescent, before starting the cycle again
. More precisely, the lunar month is the average time for the Moon to orbit the Earth and realign with the Sun, which causes the repeating pattern of lunar phases. This period is longer than the Moon’s sidereal orbital period (about 27.3 days), which is the time it takes to orbit Earth relative to fixed stars, because the Earth is also moving around the Sun during this time
. In summary:
- A lunar month is about 29.5 days long.
- It measures the time between two successive new moons (or full moons).
- It corresponds to the complete cycle of lunar phases.
- It is fundamental to lunar calendars used in various cultures
