Twenty-four solar terms sequence diagram

The order of the 24 solar terms is: beginning of spring, rain, fright, vernal equinox, Qingming, Grain Rain, Long Summer, Xiaoman, Busy, Summer Solstice, Slight Summer, beginning of autumn, Early Summer, White Dew, Autumn Equinox, Cold Dew, Early Frost, beginning of winter, Light Snow, Winter Solstice, Slight Cold and Severe Cold.

The twenty-four solar terms are determined according to the position of the sun on the ecliptic, so following the sun, the date on the tropic of cancer is basically fixed. For example, Tomb-Sweeping Day is around April 5th every year, and the winter solstice festival is around1February 22nd every year.

However, the collocation with the moon often changes, because the twelve moons are about 1 1 day less than one sun, so the date of the same solar term in a certain year is about 1 1 day later than the previous year.

folk custom

Twenty-four solar terms scientifically reveal the laws of astronomical and meteorological changes, skillfully combine astronomy, agriculture, phenology and folk customs, and derive a large number of related seasonal cultures, which have become an important part of China traditional culture. In order to express the characteristics of time series more accurately, the ancients divided solar terms into four groups: divided, arrived, opened and closed.

"Minute" refers to the vernal equinox and the autumn equinox; "Solstice" is the summer solstice and the winter solstice; "Open" is beginning of spring and Changxia, "closed" is beginning of autumn and beginning of winter. Beginning of spring, Chang Xia, beginning of autumn and beginning of winter are collectively called "Sili". "Li Si" and "divided into two" are collectively called "eight festivals", and the folks call them "four seasons and eight festivals".