How did the Millennium in the 24 solar terms come about?

1, source: The almanac says that "the bucket refers to the dew, the yin is getting heavier, and the mausoleum is the dew, hence the name dew." Entering the Millennium, the most obvious feeling is that the temperature difference between day and night is large, and it will feel a little cold at night. Although the summer heat may not leave at once, the sultry feeling will gradually fade away, adding a coolness of autumn in the morning and evening. As the weather turns cold, the sun is still hot during the day, and the sun returns to the mountains, and the temperature drops rapidly. White dew, the summer heat gradually disappears, the yin of heaven and earth rises and disperses, the night gets colder, the temperature difference between day and night widens, and the cold produces dew condensation, which is one of the reasons for "white dew".

2. The Millennium is the15th solar term in the "24 solar terms", and the third solar term in autumn is the end of the application of the moon in the dry calendar and the beginning of the unitary month. Fighting fingers; The sun reaches longitude 165 degrees; Gregorian calendar September 7-9. "White dew" is an important solar term reflecting the growth of cold in nature. As the weather turns cold, it is sunny and hot during the day, but the temperature drops quickly after evening, and the temperature difference between day and night is large.

3. When it is white dew, the summer monsoon is gradually replaced by the winter monsoon, and the cold air turns to attack. In addition, when the direct point of the sun moves south, the sunshine time in the northern hemisphere becomes shorter, the light intensity weakens, and the ground radiation dissipates quickly, so the cooling speed gradually accelerates. The Millennium basically ended the sweltering heat in summer, and the weather gradually turned cold, and the cold gave birth to dew condensation. The ancients used four seasons to match five elements. Autumn belongs to gold, gold and white alternate with each other, and autumn dew is described in white, hence the name "White Dew".

4. According to the observation of nature, the ancients in China divided the Millennium into three stages: "When the geese come, the mysterious birds return, and the birds are ashamed." This means that in this solar term, migratory birds such as Hongyan and Swallow fly south to avoid the cold, and hundreds of birds begin to store dried fruit food for the winter. At present, farmers are also busy harvesting crops. As the saying goes, "If you grab autumn, you will lose it." During the Bailuyuan period, local folk customs mainly included offering sacrifices to Dayu, brewing grain wine and drinking Bailuyuan tea.