Why is there a solar term "year"?

The names of the 24 solar terms are: beginning of spring, Rain, Sting, Vernal Equinox, Qingming, Grain Rain, Changxia, Xiaoman, Mangzhong, Summer Solstice, Xiaoshu, beginning of autumn, Chushu, Bailu, Autumnal Equinox, Cold Dew, Chufrost, beginning of winter, Light Snow, Winter Solstice, Slight Cold and Severe Cold.

The selection and arrangement of animals in the zodiac are determined according to the daily activity time of animals. Since the Han Dynasty, China used the twelve earthly branches to record the twelve hours of a day, each hour is equivalent to two hours, and it is midnight from eleven o'clock in the evening to one o'clock in the morning, when rats are most active. From 0: 00 to 3: 00 in the morning/kloc-,it's ugly, and the cow is ruminating. It is Yin Shi from 3: 00 to 5: 00. At this time, tigers are foraging everywhere, which is the fiercest. 5: 00 to 7: 00 is the crime time. At this time, the sun has not yet risen and the moon is still hanging in the sky. At this time, Yutu is busy taking medicine. 7: 00 am to 9: 00 am is the morning, which is a good time for the dragon to rain. From 9: 00 to 1 1, the snake became active. From eleven o'clock in the morning to one o'clock in the afternoon, the sun is shining, and at noon, it is the time to be unconstrained. In the afternoon 1 until 3 o'clock, it is late. At this time, sheep will grow stronger if they eat grass. From 3 pm to 5 pm, it is the Olympic Games. At this time, the monkey became active. It's one yuan from five to seven. When night falls, chickens begin to return to their nests. From 7: 00 pm to 9: 00 pm, the dog began to watch the night. From 9 pm to 1 1, it is Shihai. At this time, all was silent and the pig was snoring.