The length of daylight on the moon is about

From the earliest days, the Moon has been there in the Solar System and there has never been a period when we couldn't gaze upward in the night sky and either observe the Moon hanging there, or realize that it would be back the precise one night from now (i.e. a New Moon).

 A day on the Moon keeps going as long as 29.5 Earth days. We can say that it would take 29.5 days for the Sun to move the distance over the sky and come back to its unique position once more.

b. a lightning bug, plug of grass, and a worm

+15-35=-20

going in opposite directions