Tomb-Sweeping Day, also known as outing festival, outing festival, March festival, ancestor worship festival, etc. It was celebrated at the turn of mid-spring and late spring. Tomb-Sweeping Day is the biggest ancestor worship festival of the Chinese nation, which originated from ancient ancestor belief and spring worship custom. Tomb-Sweeping Day has two connotations of nature and humanity, which are both natural solar terms and traditional festivals. Grave-sweeping and ancestor-worship outing are two major themes of Tomb-Sweeping Day, which have been passed down since ancient times in China.

Tomb-Sweeping Day is an ancient festival of the Chinese nation. It is not only a solemn festival to pay homage to ancestors, but also a festival for people to get close to nature and enjoy spring outing. Douzhi B (or solar calendar reaches 15) is Tomb-Sweeping Day Qi, and the festival time is around April 5 of the Gregorian calendar every year.