How did the ancients time?

There are mainly 16 hour system, 10 hour system, 100 hour system, 12 hour system and the 60-point method introduced with Buddhism.

In the long history, many timing systems have appeared and many names have been produced. Generally speaking, sunrise can be called Dan, Zao, Chao and Chen, and sunrise can be called evening, dusk and evening. When the sun is in the middle, it is called noon, noon and pavilion noon, when it is near noon, it is called angle, and when it is west, it is called day and sun. After sunset, it is dusk. After dusk, it's up to people. After a person is appointed, it is midnight (or midnight). After midnight, the chicken crowed. After the cock crow, it is ignorant and dull-this is the time when it is already dawn. The ancients had two meals a day, and the last meal was before sunrise, which was called eating time or eating early; After sundial, before sunset, it is time to have dinner. This time is called "time".

As early as Shang Dynasty, the ancients invented the chronograph, whose principle was to erect a long pole on the ground and judge the time by the change of shadow length.