The 24 solar terms are divided according to the lunar calendar. By observing the annual movement of the sun, we can understand the changing laws of the four seasons, climate and phenology in a year. It not only plays a guiding role in agricultural production, but also affects the food, clothing, housing and transportation of ancient people, and even cultural concepts.

Twenty-four solar terms are not only the time criterion promulgated by successive governments, but also the compass to guide agricultural production and to predict cold, warm, snow and rainy days in people's daily life. In the field of international meteorology, the 24 solar terms are known as "the fifth invention of China". 2016165438+1October 30th, 24 solar terms was officially listed in UNESCO? List of representative works of human intangible cultural heritage.

Extended data

Division basis of 24 solar terms

The twenty-four solar terms are divided according to the position of the sun on the ecliptic (that is, the orbit of the earth around the sun). Depending on the sun starting from the vernal equinox (longitude zero, at this moment the sun shines vertically on the equator), every advance of 15 degrees is a solar term; After a week's operation, I returned to the vernal equinox, which is a tropical year with 360 degrees, so it is divided into 24 solar terms.

The dates of solar terms are relatively fixed in the solar calendar. For example, beginning of spring in the solar calendar always falls between February 3rd and 5th. However, in the lunar calendar, the date of solar terms is not easy to determine. Take beginning of spring as an example. It can be the first day of the lunar calendar in the previous year, 65438+February 15, and the latest is the first month, 15.

Baidu encyclopedia-24 solar terms