What does the Millennium in the 24 solar terms mean?

The Millennium is one of the twenty-four solar terms. At this time, the temperature began to drop, the weather turned cold and there was dew on the vegetation in the morning. The Millennium is around September 7 of the Gregorian calendar every year. In ancient China, the Millennium was divided into three stages: "When Hongyan came; Second, wait for the mysterious bird to return; Three waiting birds raise shame. " It is said that this solar term is the time when migratory birds such as geese and swallows fly south to avoid the cold, and hundreds of birds begin to store dried fruits for the winter. It can be seen that the Millennium is actually a symbol of cold weather. When the sun reaches longitude 165 degrees around September 8 every year, it is the "Millennium" solar term. "White Dew" is a festival that reflects the temperature changes in nature. Dew is a unique natural phenomenon after the solar term of "White Dew". The weather at this time, as the Book of Rites said: "The cool wind comes, the dew falls, and cicadas sing." According to the explanation of "white dew" in the twenty-four solar terms-"water and soil condense dew, autumn belongs to gold, golden white and white dew, and qi begins to be cold". The ancients also said in Xiao Weijing: "The fifteenth day after the summer heat is white dew", and the yin is getting heavier and heavier, and the dew condenses into white. "