Twenty-four solar terms refer to the specific festivals in the Ganzhi calendar that indicate seasons, phenology, climate change and the establishment of "December construction", which reflect the influence of the sun on the earth and are listed in the representative list of human intangible cultural heritage.
Twenty-four solar terms, a supplementary calendar established in the pre-Qin period in China and completely established in the Han Dynasty, is a knowledge system formed by observing the annual movement of the sun and recognizing the changing laws of seasons, climate and phenology in a year. It divides the annual movement track of the sun into 24 equal parts, and each equal part is a solar term, starting from the beginning of spring, ending in the great cold, and repeating.
"Twenty-four solar terms" reflect the annual apparent movement of the sun, so the date of "Twenty-four solar terms" in the Gregorian calendar is relatively fixed, and the difference between them is1-2 days. The earth revolves around the sun at 6: 09 10 second every 365 days, and rotates once every 24 hours. Because the orbital plane of the earth's rotation is not the same as the equatorial plane, but keeps a certain inclination, the position of direct sunlight hitting the earth is different all year round.
The jingle of the 24 solar terms table: spring rain shocks spring and clear valley days, and summer is full of mans and summer heat is connected. Autumn is exposed, autumn is cold and frost, and winter snow is small and winter is cold. The two festivals are unchanged every month, with a difference of one or two days at most. Come to June 21 in the first half of the year, and come to August 23 in the second half.
"December Construction" is a solar month based on the "twenty-four solar terms", and the division of "December Construction" is based on festivals, that is, beginning of spring, Jingzhe, Qingming, long summer, Mangzhong, Xiaoshu, beginning of autumn, Bailu, Hanlu, beginning of winter, Heavy Snow and Xiaohan are respectively regarded as Yinyue, Uzuki, Chenyue, Mitsuki, Wuyue and Xiaohan. The rest are rain, vernal equinox, Grain Rain, Xiaoman, Summer Solstice, Great Summer, Chushu, Autumn Equinox, first frost, Xiaoxue, Winter Solstice and Great Cold.