Tomb-Sweeping Day is a solar term, why is it still a festival?

Tomb-Sweeping Day is one of the twenty-four solar terms in China, and it is also an important sacrificial festival. Tomb-Sweeping Day, the tradition of the Chinese nation, began in the Zhou Dynasty.

According to legend, astronomers in the Zhou Dynasty used the method of "returning to the earth" to determine the solar terms, and Qingming is one of them. Later, Jin Wengong and Zhong Er designated the first three days of Tomb-Sweeping Day as the Cold Food Festival to commemorate the loyal minister Jiexiu. Because Tomb-Sweeping Day is close to the Cold Food Festival, Qingming has gradually integrated into the custom of ancestor worship at the Cold Food Festival. Tang Xuanzong directly packaged Tomb-Sweeping Day and Cold Food Festival into national legal holidays. Later, Tomb-Sweeping Day gradually absorbed the custom of going for an outing at Shangsi Festival, and gradually rose from a simple agricultural solar term to an important festival.