The Start of Winter, also known as Li Dong, is the 19th solar term of the 24 solar terms in the traditional Chinese lunar calendar. It marks the beginning of winter, when the climate transitions from the dry and rainy autumn to the cold and frosty winter.

During this period, the sun reaches the celestial longitude of 225°, typically falling on November 7th or 8th each year. It signifies the closure of qi (life energy), and all things enter a state of recuperation and collection. In northern China, people have a custom of eating dumplings on this day, believing it can prevent their ears from freezing in winter.