How have humans kept track of time?

Humans have used clever tools and ideas to keep track of time, just like how you use a clock to know when it's snack time or bedtime.

At first, people watched the sun, when it came up, that was morning; when it went down, that was night. It was like having a giant, glowing clock in the sky. They used this to divide days into parts: sunrise to sunset was a day, and then they counted how many of those happened to make a year.

Later, people made water clocks, which were like a slow drip of water from one container to another, each drop showed time passing, just like counting beads on an abacus.

Then came the sundial, a flat piece with a stick that cast a shadow. As the sun moved across the sky, the shadow changed position, telling people what hour it was, kind of like how your shadow moves when you walk across the playground at different times of day.

Eventually, humans made clocks with hands that moved around numbers, and even today we use them to know when to wake up or go to bed. Timekeeping has come a long way, from the sun to the tick-tock of clocks!