When did the folk winter festival in China begin?

China folk "winter of 1999" started from the winter of solstice.

Jiujiu, also called Jiujiu in winter, is a folk method in China to calculate the flowering date in cold weather and warm spring. Generally, March 9 and April 9 are the coldest days of the year. When you count to nine "nine days" (998 1 day), spring will be deep and warm, and everything will be full of vitality. It's time for spring ploughing.

Winter solstice, also known as solstice, winter festival, child year, etc. It has both natural and humanistic connotations. It is not only an important solar term among the 24 solar terms, but also a traditional folk ancestor worship festival in China. The solstice in winter is one of the eight festivals in four seasons, and it is considered as a big holiday in winter. In ancient times, there was a saying that the winter solstice was as big as a year. The custom of winter solstice varies in content or details due to different regions. In southern China, there are customs of offering sacrifices to ancestors and enjoying the winter solstice. In northern China, it is a custom to eat jiaozi from winter to Sunday every year.