Definition:Time/Unit/Month

Definition

The month is a derived unit of time.

The month is measured only approximately in duration, and is not used as a scientific measure.

$1$ month is between $28$ and $31$ days, depending on which month it is.

The lunar month is defined as the length of time between $2$ new moons.

$1$ lunar month $\approx 29 \cdotp 530588$ days

or:

$1$ lunar month $\approx 29$ days, $12$ hours, $44$ minutes and $2 \cdotp 8$ seconds.

The word month derives from the word moon, from its definition as the approximate duration of one full cycle of phases from new moon to new moon.