24 solar terms and Song used these methods of explanation.

The method of analogy and antithesis was used in the song dynasty of the twenty-four solar terms.

1, summer solstice, winter solstice: It means hot summer and cold winter are coming. The hottest month in China is July, and the summer solstice is June 22nd, which indicates that the hottest summer is coming. The coldest month in China is 65438+ 10 month, and the winter solstice is 65438+February 23rd, which means that the coldest winter is coming, so it is called summer solstice and winter solstice respectively. Because the solstice day in summer is the longest and the solstice day in winter is the shortest, it is also called long day and short day in ancient times.

2, vernal equinox, autumnal equinox: it means that day and night are equally divided. These two days are equal day and night, which were collectively called day and night in ancient times. These two solar terms are between beginning of spring and Changxia, and between beginning of autumn and beginning of winter, which divide the spring and autumn into two halves, so there is also reason to explain the vernal equinox and the autumnal equinox.

3. As the saying goes, "Flowers and trees control the four seasons, and birds sing to report the farming season". Flowers, trees, birds, beasts and birds all move with the seasons, so their regular movements are regarded as an important symbol to distinguish seasonal solar terms.

4. In ancient China, the Great Cold was divided into three stages: "One stage is chicken milk; Second, the symptoms of bird disease; Three times, the water is strong. " In other words, chickens can be hatched in the cold solar terms. The cold climate in Hua Xinfeng is "Daphne, Orchid and Alum (born in Jiangnan)". It can also be used as an important sign to judge the severe cold.

5. Spring represents warmth and growth. In the era of main branches, beginning of spring is the beginning of a year, and beginning of spring is the beginning of spring and the beginning of a year. In ancient times, it was not the first day of the first month, but the beginning of spring. Major ceremonies, such as worshipping God and ancestors, praying for a new year, welcoming spring and agriculture, are arranged at the beginning of spring and the days around it.