How to divide the festival and sum in the twenty-four solar terms

The first solar term of each month is "solar term", namely: beginning of spring, Jing Zhe, Qingming, Long Summer, Mangzhong, Xiaoshu, beginning of autumn, Bailu, Cold Dew, beginning of winter, Heavy Snow and Slight Cold;

The second solar term of each month is "Zhongqi", that is, the twelve solar terms: rain, vernal equinox, Grain Rain, Xiaoman, summer solstice, great summer heat, early Shu, autumn equinox, first frost, light snow, winter solstice and great cold.

The rounded corner of the earth's orbit around the sun is 360 degrees. According to the climate change of direct sunlight in different parts of the earth, our ancestors divided a solar term every 15 degrees, and each solar term was about 15 days apart. In this way, there are two solar terms every month, twelve months a year, which just synthesize twenty-four solar terms.

The earth rotates once a day and revolves around the sun once a year. Solar terms are divided according to the orbit position of the earth around the sun and the angle formed by the oblique intersection of the earth's rotation axis (the connecting line between the north and south poles of the earth) and the orbit (the ecliptic plane). Twenty-four solar terms, that is to say, the earth has twenty-four different positions in the orbit of revolution.