How many seconds in a day on the Moon?

Answer 1

The Moon is "tidally locked" and always has the same face turned to the Earth.

So, the rotation period equals the orbital period.

The Moon rotates once (a sidereal day) per 27.321582 Earth days.

So, that's the length of the Moon's "sidereal day".

The "daylight" is about 14 days long, and the nights are about the same length.

(If you're on the "near side" of the Moon, then the lunar night is at least sort-of illuminated by the nearly full Earth, which is WAY brighter than the full Moon.)

So the answer is: about 2,360,580 seconds.