What is the ancient notation of time?

The ancient time notation is: chronology, twelve branches.

Chronology of a day: Sunrise is called Dan, Zao, Chao and Chen, and Sunrise is called Late, Sunset and Faint. When the sun is in the center, it is called noon, and when the sun is close to noon, it is called angle. When the sun goes down, it is called a sundial.

The ancients had two meals a day, and the eclipse was after sunrise and before the corner, which was called food time; The night eclipse is after the sundial and before the sun enters, which is called sunset. The above method of dividing time periods was widely adopted in the Zhou Dynasty.

After the early Han Dynasty, the twelve earthly branches were named as twelve hours, and each hour was exactly equal to two modern hours. In modern times, every hour is subdivided into the beginning and the right, which is equivalent to dividing a day and night into twenty-four equal parts.

solar term

In ancient China, agricultural production was guided by observing images and time. The ancients divided the week around the ecliptic into twenty-four equal parts. According to the twenty-four different apparent positions of the sun on the ecliptic, it is actually twenty-four different positions of the earth in its orbit around the sun.

The whole year is divided into twenty-four solar terms, including twelve "festival" qi such as beginning of spring and Jing Zhe, and twelve "moderate" qi such as rain and vernal equinox, which are collectively called "twenty-four solar terms" to reflect the changes of seasons, temperature, rainfall and phenology. The division of the twenty-four solar terms originated from the Yellow River Basin in China. The ancients first discovered dichotomy and dichotomy.