What are the twelve solar terms divided into?

Definition of scientific and technological terms

English name: 24 solar terms English name: 24 solar terms definition 1: According to the position of the sun on the ecliptic, we divide 24 seasons and climates that reflect the natural phenomena and seasonal characteristics of farming in a certain area of China (represented by the middle and lower reaches of the Yellow River). Namely, beginning of spring, Rain, Sting, Vernal Equinox, Qingming, Grain Rain, Changxia, Xiaoman, Mangzhong, Summer Solstice, Xiaoshu, Dashu, beginning of autumn, Chushu, Bailu, Autumnal Equinox, Cold Dew, First Frost, beginning of winter, Light Snow, Heavy Snow, Winter Solstice, Slight Cold and Severe Cold. Applied discipline: atmospheric science (first-class discipline); Definition 2 of applied meteorology (two disciplines): The position of the sun on the ecliptic reflects the natural phenomenon and seasonal characteristics of farming in a certain area of China (represented by the middle and lower reaches of the Yellow River). Namely, beginning of spring, Rain, Sting, Vernal Equinox, Qingming, Grain Rain, Changxia, Xiaoman, Mangzhong, Summer Solstice, Xiaoshu, Dashu, beginning of autumn, Chushu, Bailu, Autumnal Equinox, Cold Dew, First Frost, beginning of winter, Light Snow, Heavy Snow, Winter Solstice, Slight Cold and Severe Cold. Applied discipline: geography (first-class discipline); Climatology (two disciplines) definition 3: 24 solar terms and climate reflecting the seasonal characteristics of natural phenomena and agricultural activities in a year. Namely, beginning of spring, Rain, Creeping, Vernal Equinox, Qingming, Grain Rain, Changxia, Xiaoman, Mangzhong, Summer Solstice, Xiaoshu, Dashu, beginning of autumn, Chushu, Bailu, Autumnal Equinox, Cold Dew, Chufrost, beginning of winter, Light Snow, Heavy Snow, Winter Solstice, Slight Cold and Severe Cold. Applied discipline: resource science and technology (first-class discipline); Climate resources science (two disciplines)

Twenty-four solar terms, a supplementary calendar to guide farming in ancient China, were formed in the Spring and Autumn Period and the Warring States Period. 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. Twenty-four solar terms can reflect the changes of seasons, guide agricultural activities and affect the food, clothing, housing and transportation of thousands of families. The twenty-four solar terms are divided according to the position of the sun on the ecliptic (that is, the orbit of the earth around the sun).