On what basis did the ancients initially determine the 24 solar terms? What are the characteristics of each solar term?

Twenty-four solar terms are the material of ancient farming civilization, which contains the long-standing cultural heritage and historical and cultural accumulation of Chinese culture. At first, it was based on the substitution of flowers and trees. According to the deviation of the Big Dipper in the night sky, the ancients specially guided the busy farming season. During the period of Emperor Wu of the Western Han Dynasty, taichu calendar listed the "Twenty-four solar terms" as a supplement to the lunar calendar, which specially guided agricultural work, and used the standard chart drawing method to calculate the festivals in the Weihe River basin. The current standard "24 solar terms" comes from the zoning according to the myopia degree of sunlight and yellow sun signed more than 300 years ago.

In the development of historical time, the "24 solar terms" have been incorporated into the lunar calendar and become a key part of the lunar calendar. The 24 solar terms show the wisdom of our ancient ancestors. The twenty-four solar terms had a very important influence on ancient agriculture. Many farmers used to distinguish between harvesting seeds and planting crops according to the 24 solar terms. We are also using the 24 solar terms now, which is of great significance to modern society. The twenty-four solar terms are vernal equinox, precipitation, fright solar term, beginning of spring, Tomb-Sweeping Day, vernal equinox, slight summer heat, Xiao Man solar term, awn seed, summer solstice and slight summer heat.

Little summer, cold dew, big summer, cold dew, beginning of autumn, winter solstice, frosting, winter solstice, drought, snow, winter solstice solar terms, slight cold solar terms, slight cold. These 24 solar terms are of great significance to the development of modern agriculture in ancient times. It is also one of the main reasons for the invention of the twenty-four solar terms. Twenty-four solar terms are a long-term knowledge structure generated by ancient Chinese people according to the review and summary of the annual fitness exercise of the sun. There are styles in some ancient books, and three key methods are used in the 24 solar terms, namely, grafting method, mapping method and Huang Chi intersection method.

The summer solstice is not only a festival, but also one of the oldest festivals. Ancient people worshipped God and ancestors on the day of summer solstice and prayed for disaster-free and prosperous next year. Among the folk customs, the popular custom is to eat noodles on the solstice in summer, which is what we often say, "Eating noodles on the solstice in winter in jiaozi". Because the new wheat is perfect around the summer solstice, eating noodles on this day also means tasting new things. There is also the custom of weighing people on this day. In summer, people usually lose their appetite and lose weight because of the heat. Therefore, we weigh ourselves on the solstice of summer until the cold dew, for comparison.