Night is the period when your part of Earth has rotated away from the sun, making the sky dark. While you sleep through most of it, night begins at sunset and lasts until sunrise the next morning.

For thousands of years, night shaped how humans lived. Before electric lights, people worked during daylight and rested after dark, reading or talking by candlelight or firelight. Farmers still call the time between sunset and sunrise nighttime, even though cities now glow brightly enough to hide most stars.

The darkness of night happens because Earth spins like a top. As your location rotates away from the sun, its light can't reach you anymore, the same way the back of your head stays in shadow when you face a lamp. Meanwhile, people on the other side of Earth are experiencing day.

Night isn't the same everywhere. Near the equator, nights stay about twelve hours long year round. But near the North and South Poles, winter brings months of continuous night, while summer brings months of continuous daylight.

You might also hear night used to mean evening, as in “movie night” or “game night,” referring to activities that happen after dinner, whether it's fully dark yet or not.