The fourth day of the Chinese New Year is a big day for Chinese families since it is the day the Kitchen God comes back from Heaven and brings back blessings.
Believed to be the protector and supervisor of Chinese families, the Kitchen God would go back to Heaven and report to the Jade Emperor right before every Chinese New Year. Chinese people believe that by eating sweets, your mouth also turns sweet. Chinese people would even "bribe" him by serving sweet snacks to him seven days before the Spring Festival comes to make the Kitchen God praise their families to the Jade Emperor.
This legend has also shaped the way the Chinese behave into patterns of politeness and humbleness.