Twenty-four solar terms in Song Dynasty, what do you mean? What's the point?

Meaning: After experiencing the weather in beginning of spring, rain, fright, spring equinox, Qingming and Grain Rain, we arrived at Long Summer, Xiaoman, Miscanthus, Summer Solstice, Slight Summer, Great Summer, beginning of autumn, Summer Heat, White Dew, Autumn Equinox, Cold Dew, First Frost, beginning of winter, Light Snow, Heavy Snow, Winter Solstice, Slight Cold and Great Cold.

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 term song" is a small poem compiled for the convenience of remembering the twenty-four solar terms in the ancient calendar of China, and there are many versions circulating. Solar terms refer to 24 solar terms and climate, which is a calendar made in ancient China (note 1) to express seasonal changes and guide farming, and is the crystallization of long-term experience and wisdom of working people in ancient China.

Because the lunar calendar in China is a kind of "yin and yang calendar", which is based on the movement of the sun and the moon, it can't fully reflect the solar cycle. But China is an agricultural society, and agriculture needs a strict understanding of the movement of the sun, so farming is entirely based on the sun. Therefore, the "twenty-four solar terms" that reflect the solar cycle alone are added to the calendar as the standard for determining leap months.