1 Origin of the winter solstice: The winter solstice is one of the "twenty-four solar terms". During the period of Emperor Wu of the Han Dynasty, twenty-four solar terms were absorbed into the taichu calendar as a supplement to the calendar guiding farming, and the solar terms were divided by the method of "balancing qi" (that is, the average time method). "Pingqi Method" uses photogrammetry to determine the shortest day in the Yellow River basin as the winter solstice, divides the date between the winter solstice and the next winter solstice into twelve equal parts, which is called "Zhongqi", and then divides the dates between adjacent "Zhongqi" into equal parts, which is called "solar terms"; On average, there is a "neutral gas" and a "solar term" every month, which are collectively called "24 solar terms".

2, the winter solstice custom:

(1) jiaozi and wonton are eaten in the north. In northern China, there is a custom of eating jiaozi on the winter solstice. On this day every year, jiaozi is an indispensable holiday meal for the rich and the poor. According to legend, this custom is to remember the kindness of Zhang Zhongjing, a "medical sage", in "Quhan Jiaoer Decoction". The significance of winter solstice wonton is mainly sacrifice, followed by eating. Some ancient people thought that eating wonton on the winter solstice was to break the yin and release the yang and support the growth of yang between heaven and earth.

(2) Eating glutinous rice balls in the south. Eating glutinous rice balls on the winter solstice is a traditional custom in China, especially in the south of the Yangtze River. There is a saying among the people that "eating glutinous rice balls is one year older". Tangyuan can be used to worship ancestors, to give gifts to relatives and friends, and to represent the meaning of reunion.