Because it means that the year is coming to an end and people are one year older. Eating glutinous rice balls during the winter solstice is a traditional custom in my country, especially popular in Jiangnan. There is a saying among the people that "eating glutinous rice balls makes you one year older". Tangyuan is also called glutinous rice balls, and eating glutinous rice balls during the Winter Solstice is also called "winter solstice dumplings". Tangyuan can be used to worship ancestors or as gifts to relatives and friends.

Among the 24 traditional solar terms, the winter solstice is a more important one. There was once a saying that "the winter solstice is as big as the new year". The ancients believed that the winter solstice was the natural transformation of yin and yang and a blessing from God.

In the Han Dynasty, the Winter Solstice was regarded as the "Winter Festival", and the government would hold a congratulatory ceremony called "Winter Congratulations" and have a routine holiday. During the Tang and Song Dynasties, the winter solstice was a day for worshiping heaven and ancestors. On this day, the emperor would go to the countryside to hold a ceremony to worship heaven, and the people would worship their parents and elders on this day. After thousands of years of development, the Winter Solstice has formed a unique seasonal food culture. In the south, glutinous rice balls are generally eaten, which means "reunion" and "completeness".