Beginning of spring, Rain, Sting, Equinox, Qingming, Grain Rain, long summer, Xiaoman? , Miscanthus, Summer Solstice, Slight Summer, Great Summer, beginning of autumn, Chushu, Bailu, Autumnal Equinox, Cold Dew, first frost, beginning of winter, Light Snow, Heavy Snow, Winter Solstice, Slight Cold and Great Cold.

Definition of words:

Solar terms can be understood in two ways:

One of the twenty-four solar terms. Since the slight cold, every increase of15 of the solar meridian is another solar term. There are 24 solar terms: slight cold, beginning of spring, Jing Zhe, Qingming, long summer, Mangzhong, Xiaoshu, beginning of autumn, Bailu, Hanlu, beginning of winter and Daxue. Called the twelve solar terms.

Second, the general term for the twenty-four solar terms. Solar terms are generally calculated according to the lunar calendar.

The earth revolves around the sun at 5: 48: 46 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. In the northern hemisphere, when the sun is directly at 23.5 degrees north latitude, it is called the summer solstice in astronomy; When the sun shines directly at 23.5 degrees south latitude, it is called the winter solstice; The summer solstice and the winter solstice mean that it has reached the middle of summer and winter. When the sun shines directly on the equator twice a year, it is the vernal equinox and the autumnal equinox, which is in the middle of spring and autumn. The days are as long as the nights. The solar terms reflecting the changes of the four seasons are: beginning of spring, Spring Equinox, long summer, Summer Solstice, beginning of autumn, Autumn Equinox, beginning of winter and Winter Solstice. Among them, beginning of spring, long summer, beginning of autumn and beginning of winter all called "four stands", which means the beginning of the four seasons. There are five solar terms reflecting temperature changes: slight summer heat, great summer heat, summer heat, slight cold and great cold. There are seven solar terms reflecting weather phenomena: rain, Grain Rain, Bailu, Cold Dew, first frost, light snow and heavy snow. There are four solar terms that reflect the phenological phenomenon: fright, Qingming, Xiaoman and Mangzhong.

Solar terms refer to the moment, that is, when the solar longitude is equal to 15 degrees, it is Tomb-Sweeping Day.

Historical origin:

In ancient China, the sundial was measured by Tugui, and the longest day shadow was defined as "Solstice" (also known as the day is full, the day is long, and the winter solstice), and the shortest day shadow was "Short Solstice" (also known as Short Solstice and Summer Solstice). In spring and autumn, there is a day with the same length of day and night, which is designated as "vernal equinox" and "autumn equinox". There were only four solar terms in Shang Dynasty, but it developed to eight in Zhou Dynasty, and the twenty-four solar terms were completely established in Qin and Han Dynasties. In BC 104, taichu calendar, written by Deng Ping, officially set the 24 solar terms in the calendar, and defined the astronomical position of the 24 solar terms.

The names of the twenty-four solar terms first appeared in Huai Nan Zi Tian Xun, and the concepts of Yin and Yang, four seasons, eight places, twelve degrees and twenty-four solar terms were also mentioned in the preface of Historical Records Taishigong. During the reign of Emperor Wu of the Han Dynasty, Luo Xiahong compiled the solar terms into the taichu calendar, and stipulated that the month without neutral gas was the leap month of last month.

Each of the 24 solar terms corresponds to a certain position reached by the sun for every movement15 on the ecliptic. Twenty-four solar terms are divided into 12 solar terms and 12 neutral terms, one by one. The twenty-four solar terms reflect the annual apparent movement of the sun, so their dates are relatively fixed in the Gregorian calendar. The solar terms in the first half of the year are on the 6th, the solar terms in the second half are on the 8th, and the solar terms in the second half are on the 23rd, which are not different1~ 2.

The naming of the twenty-four solar terms reflects three kinds of seasons, phenology and climate change. The response seasons are beginning of spring, vernal equinox, long summer, summer solstice, beginning of autumn, autumn equinox, beginning of winter and winter solstice, also known as eight; The phenological phenomena are fright, Qingming, Xiaoman and Mang. Rain, Grain Rain, Slight Summer, Great Summer, Chu Summer, White Dew, Cold Dew, first frost, Light Snow, Heavy Snow, Slight Cold and Severe Cold are the responses to climate change. [ 1]