How did the ancients explore and determine the 24 solar terms?

Although the new moon is convenient for timing, it is difficult to reflect climate change. So people try to divide a solar year into several smaller periods, one is to reflect climate change in detail, and the other is to meet the needs of leap. The result of the exploration was finally determined as 24 solar terms.

The twenty-four solar terms were gradually formed on the basis of the sundial measured by the soil, not later than the Spring and Autumn Period. Spring, summer, autumn and winter are its eight basic points, and every two points are divided into three sections on average, named after the corresponding meteorological and phenological phenomena respectively.

The systematic record of the twenty-four solar terms began with Zhoupian and Huainanzi. It accurately reflects the relationship between the sun and the earth formed by the revolution of the earth, which is very consistent with the cold, warm, dry and wet climate changes in the Yellow River basin in a year, and it is more convenient to grasp the agricultural time according to the full moon and short month. It is a great creation of indicating time mode in China's agriculture, and it still plays a guiding role in agricultural production.