Eating glutinous rice balls on the solstice in winter is a traditional custom in China, especially in the south of the Yangtze River. There is a folk saying that "eating glutinous rice balls is one year older". Tangyuan is also called Tangtuan, and eating it on the solstice in winter is also called "the solstice reunion in winter".
There was a custom of eating glutinous rice balls in Tang and Song Dynasties. At first, people held large-scale sacrificial activities from the winter solstice to the sun. On this day, women get up early to prepare food for sacrifice, and then wrap a pot of glutinous rice balls. When the sacrificial people come back, the whole family sits around and eats hot glutinous rice balls, which also means reunion.
3. The winter solstice is the starting point for calculating the 24 solar terms. Because the solstice of winter is coming, the New Year is just around the corner. Shang dynasty, Zhou dynasty and Qin dynasty all designated the winter solstice as the "first year", and Han dynasty began to designate it as the "winter festival". There is a folk saying that "the solstice in winter is as big as a year", which means that the custom of the solstice in winter is almost the same as celebrating the New Year.