Isn’t it nice how our planet spins around every 24 hours? We go to bed at night and it’s still hot. But when we wake up, it’s nice and cool. Imagine if our planet only rotated every 116 days. Then we’d never have the chance to cool off. It would get hotter and hotter. Yipes!
Here are the other planets day lengths for how long the Sun takes to go once around the sky, which is called the synodic period of rotation.
Mercury..175.940 days Venus....116.75 days (2,784 hours) Earth.....24 hr 0 min 0 sec Moon......29.53 days Mars......24 hr 39 min 35.24 sec Jupiter....9 hr 55 min 33 sec Saturn....10 hr 32 min 36 sec Uranus....17 hr 14 min 23 sec Neptune...16 hr 6.6 min Pluto.....6 days 9 hr 17.0 min
And for you people who think you are smarty pants, and say that it’s actually 23 hr 56 min 4.1 sec for the length of Earth’s day. Well, that’s the time it takes earth to rotate, yes (called the Sidereal Period). But if you factor in that the Earth rotates around the sun. And we are counting how long it takes the sun to rise and fall, then that is the Synodic Period or what we know as “Day.” (source)