How did Qingming change from solar terms to festivals?

Tomb-Sweeping Day has changed from a solar term to a festival to commemorate ancestors. According to records, it is related to the Cold Food Festival.

Cold Food Festival is an early festival in ancient China. Legend has it that it was set up in the Spring and Autumn Period to commemorate Jiexiu, a loyal minister of the State of Jin. However, from the actual history, the prohibition of fire and cold food actually mainly reflects the remains of the custom of changing fire in China.

During the Cold Food Festival, the customs mainly included forbidding fire, cold food and offering sacrifices to sweep graves, which later became the main content of Tomb-Sweeping Day. China people attach great importance to offering sacrifices to their ancestors. During the Qin and Han Dynasties, sweeping graves became more popular.

In the Tang Dynasty, both literati and civilians regarded sweeping graves at the Cold Food Festival as a ceremony to return to their ancestral home. Because Tomb-Sweeping Day is close to the Cold Food Festival, people often postpone sweeping graves to Tomb-Sweeping Day. Poets' works are often cold food and clear food. For example, Bai Juyi said, "Crows call trees faint, and those who eat cold food and clear food cry." Wei: "Qingming cold food is good, and the spring garden is full of flowers."

During the Song and Yuan Dynasties, Tomb-Sweeping Day gradually replaced the Cold Food Festival. This is not only reflected in the fact that many ceremonies such as sweeping graves to worship ancestors are held in Qingming Festival, but also the original customs and activities of cold food festivals such as cold food, cuju and swinging are accepted by Tomb-Sweeping Day.