how long is a day
What you have come to understand as a day is classified by astronomers as a solar day. It's the amount of time it takes for the sun to move through the sky and return to roughly the same spot. This is different from the amount of time it takes for the Earth to turn once on its axis â the 23 hours, 56 minutes. Also known as a sidereal day. Axis of the Earthâs pole.