Does anyone know about the solar term Song?

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

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

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; Bucket handle refers 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 of the "years 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.