How did the twenty-four solar terms come about? In the 2 1 century, does it still exist?

Twenty-four solar terms originated in the Yellow River Basin. As early as the Spring and Autumn Period, four solar terms were set, namely, mid-spring, mid-summer, mid-autumn and mid-winter. After continuous improvement and perfection, by the Qin and Han Dynasties, the 24 solar terms had been completely established. In BC 104, the taichu calendar written by Deng Ping officially set 24 solar terms in the calendar, and defined the astronomical position of the 24 solar terms.

Twenty-four solar terms objectively reflect seasonal changes and climate changes, and are the signs of phenological changes and seasonal order in China. Its formation and development are closely related to the development of agricultural production in China. After the rise of modern agro-meteorology, many regions combined the 24 solar terms with agro-meteorological data, and compiled agricultural climate calendars, agricultural calendars or agricultural activity tables, which combined ancient experience with modern science and technology and brought out the best in each other, and continued to play a role in modern agricultural production.