What do the 24 solar terms in China mean?

The twenty-four solar terms in China represent twenty-four different positions of the earth in the orbit of revolution. Because it takes 365 days for the earth to go around the sun, there is a solar term every fifteen days, and each solar term represents different changes in climate, phenology and time.

The start date of the twenty-four solar terms is almost the same every year in the solar calendar, with a difference of one or two days at most, which is precisely because the solar terms, like the solar calendar, are based on the earth's orbit around the sun once a year. According to the law of the operation of heaven and earth, the ancients determined the starting point and ending point of the four-season cycle and divided the 24 solar terms.

The ancients divided the sun's annual trajectory into 24 equal parts, each of which is called a "solar term", collectively called "24 solar terms", including: beginning of spring, rain, fright, vernal equinox, Qingming, Grain Rain, long summer, Xiaoman, Miscanthus, summer solstice, slight summer heat, great summer heat, beginning of autumn, Chushu, Bailu, autumnal equinox and cold dew.

Among the 24 solar terms, winter solstice, severe cold, rain, vernal equinox, Grain Rain, Xiaoman, summer solstice, summer heat, summer heat, autumn equinox, first frost and light snow are neutral, which are usually used to determine the month. The winter solstice month must be winter month (1 1 month), cold month must be December (1February), rainy month must be January, vernal equinox month is February, and light snow month is October. ? The interval between gas days is about 5.25 hours on the 30th, so the interval between gas days (including before and after) is 30 or 3 1 day. And a month's time is 29 or 30, and a month is either neutral or not. So neutral gas can directly determine the month and leap, and the month without neutral gas is the leap month of the previous month.

The twenty-four solar terms are divided according to the position of the earth 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.

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. Twenty-four solar terms accurately reflect seasonal changes, which are used to guide agricultural activities and affect the food, clothing, housing and transportation of thousands of households. The twenty-four solar terms scientifically reveal the laws of astronomical and meteorological changes.

People in different regions and different times combined with the climate and agricultural planting conditions at that time, kept pace with the times and localized the 24 solar terms. Since modern times, according to the changes of temperature, precipitation and phenology, farmers have constantly given new connotations to solar terms, and dynamically revised and improved agricultural proverbs related to solar terms.

Refer to Baidu Encyclopedia-24 solar terms