A lunar day is the period of time for

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surf ...

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width ...

to complete one rotation on its axis with respect to the Sun. Due to tidal locking, it is the time the Moon takes to complete one

orbit In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such a ...

around

( Earth rise to Earth set) plus about 2.2 more Earth days to return to the same Moon phase (due to the Moon's orbit around the Sun). The lunar day is roughly 29 Earth days, the length of a lunar month, and the time of which includes a full

day-night cycle A diurnal cycle (or diel cycle) is any pattern that recurs every 24 hours as a result of one full rotation of the planet Earth around its axis. Earth's rotation causes surface temperature fluctuations throughout the day and night, as well as we ...

Main definition

Relative to the fixed stars on the celestial sphere, the Moon takes 27 Earth

day A day is the time period of a full rotation of the Earth with respect to the Sun. On average, this is 24 hours, 1440 minutes, or 86,400 seconds. In everyday life, the word "day" often refers to a solar day, which is the length between two so ...

s, 7