Why do day and night occur?

... the sky, it is day, and when you don't it is night. So the real question is "why is the Sun in the sky at some times and not at others?" We can see that the Sun seems to move across the sky starting in the east in the morning, moving toward the south at noon, and then toward the west as the day ends. How does this happen? read more

Day and night occur because of the rotation of a planet around its axis. The hemisphere of the planet that faces the sun at a particular moment experiences daylight, while the opposite side experiences darkness. read more

As a result of seasonal changes that happen with every passing year, the length of day and night can vary – and be either longer or shorter – by just a few hours. But in some regions of the world (i.e. the poles) the Sun does not set during certain times of the year. read more