Why is the first day of February called Jiujiu?

The first day of February this year is also the "September 9" among the 99 solar terms. According to the old custom, the 99 solar terms are also called "counting nine".

In ancient China, the Jiujiu song: 1929 didn't shoot; in 3949, I walked on the river; in 5969, I watched the willows along the river; in 79, I opened the river; in 89, the geese came; in 99 and 19, I plowed cattle everywhere.

The concrete significance of counting nine songs

The ninth song is a ballad reflecting the solar terms in winter. It takes nine as the unit, one * * * nine nines, and * * * is 8 1 day, describing the natural change from cold to warm in winter.

Since the first nine days, the weather has become so cold that people can only put their hands in their pockets; In 3949, it was the coldest day in winter, and even the water in the river was frozen into ice, so it was not a big problem for people to walk on the ice. In May, 1969, the weather became warmer and the willows along the river sprouted.

When the ice of the 79 River melts into water, the water begins to warm. By August 9, the swallows had flown back from the south, and it was a lively scene; 1999, people began to work in the fields and prepare for farming. In ancient times, people used Niu Gengdi, so they could plow cattle everywhere.