Solar term song is simple.

The spring rain shakes the spring and clears the valley, and the summer is full of mountains and summers.

Autumn dew, autumn frost, little snow in winter and cold in winter.

The two festivals remain unchanged every month, with a maximum difference of one or two days.

The first half of the year is June 2 1 day, and the second half is August 23.

Twenty-four solar terms were established in ancient times. The rotation of the Big Dipper is closely related to the change of seasons: "bucket handle refers to the east, and the world is spring; Bucket handle guide, the world is summer; Bucket handle refers to the west, and the world is autumn; " The handle of the bucket points to the north, and it is winter all over the world. In ancient times, bucket handle's direction-the Big Dipper was used as the standard to judge the season, which was called sword fighting, also known as Jian Yue.

Bucket handle revolves around the east, south, west and north, which is called "one year old" (Figure). It began in the beginning of spring and ended in the great cold. In BC 104, taichu calendar written by Deng Ping absorbed 24 solar terms as a supplement to the calendar. Based on the Yellow River Basin. Divide the year into 24 segments, about 15 days.

The current 24 solar terms come from the law of fixed space more than 300 years ago, that is, the time when the sun runs along the ecliptic from zero 15 degrees is called "a solar term". It runs 360 degrees every year, and * * * experiences 24 solar terms, twice a month.

Among them, the first solar term of each month is "solar term", that is, beginning of spring, Jing Zhe, Qingming, Long Summer, Mangzhong, Xiaoshu, beginning of autumn, Bailu, Hanlu, beginning of winter, heavy snow and slight cold. 12 solar terms; The second solar term of each month is "Zhongqi", that is, there are 12 solar terms such as rain, vernal equinox, Grain Rain, Xiaoman, summer solstice, great heat, intense heat, autumnal equinox, first frost, light snow, winter solstice and great cold.