What does it mean to eat jiaozi for thirty nights?

It means a bumper harvest in the coming year, in memory of Pangu and Nuwa.

Jiaozi is a classic traditional food in China. Jiaozi is eaten on New Year's Eve mainly because the shape of jiaozi is similar to that of an ingot. People think that eating jiaozi can get beautiful meanings, such as a bumper harvest and getting rich, and New Year's Eve is the combination point to bid farewell to the old and welcome the new, so they will choose to eat jiaozi. In addition, this custom is also related to legends. It is said that Pangu lifted the chaotic state of the world after the creation of the world, and then gradually evolved into a child. Therefore, in order to commemorate Pangu, people will eat jiaozi on New Year's Eve to commemorate Pangu. Another legend is to commemorate that Nu Wa created ears for human beings. On New Year's Eve, when people eat jiaozi, they also put in candy and coins. When they eat jiaozi with coins and candy, it means getting rich and good luck.