What is the ninth song?

Jiujiu Song: 1929 without lens; Walking on the ice in 3949; 5969 see willows along the river; 79 rivers open 89 geese; 99 plus 19, plowing cattle everywhere. The winter solstice is the 22nd solar term of the lunar calendar, which is also called "nine to nine" or "nine to nine", that is, from the winter solstice, there will be a "nine to nine". When this number reaches 8 1 day, it will be "nine peach blossoms" in the south. ?

From the meteorological point of view, there is a cold wave every nine days, which is called nine, and often occurs at the end of the first nine; From the psychological aspect of fear of cold, "nine" and "long" are homophonic, indicating that cold days are long. Every winter solstice, the ancients cooled down day by day, hoping that spring would come early. The coldest days are usually three or nine days.

Extended data:

Because the earth has accumulated cold and hot energy some time ago, there are still 40 days of coldest weather from winter to the future; 18 solstice after beginning of winter, stiff hands and feet; The period from 18 days after beginning of winter to 36 days 18 days is the coldest period in a year, with the river surface frozen and the river blocked. Once winter comes to 18 days from 36 days to 54 days in the future, willows along the river will sprout new buds and the climate will get warmer; From winter to the 54th day to the 63rd day, geese fly back to the north from the south. From winter to 63-72 days in the future and beyond, the weather will be completely warm after spring ploughing.

Baidu encyclopedia-counting nine winters