How to determine the number of solar terms?

The time when the sun runs along the longitude of the Yellow River 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, Jingzhe, Qingming, Changxia, Mangzhong, Xiaoshu, beginning of autumn, Bailu, Hanlu, beginning of winter, Heavy Snow, Xiaohan, etc. 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, summer heat, summer heat, autumn equinox, first frost, light snow, winter solstice and great cold.

"Solar term" and "neutral qi" appear alternately, each lasting 15 days. Now people have called "solar terms" and "neutral gas" solar terms.

Solar terms calculation formula: beginning of spring date calculation formula: [y * d+c]-L.

Twenty-four winds, also known as twenty-four, are called symplectic because they come from flowering period. As the saying goes, "flowers and trees control the four seasons, and birds sing to report the farming season." Flowers, trees, birds and animals in nature all move according to certain seasons, and their activities are closely related to climate change.

Therefore, their activities have become the symbols of seasons, such as the bud, leaf development, flowering, fruiting, yellow leaves and deciduous leaves of plants, dormancy, resuscitation, first sound, reproduction and migration of animals, etc. All these are restricted by climate change. People call these rhythmic natural phenomena phenology.