Smart Festival refers to Tomb-Sweeping Day, which is another name for Tomb-Sweeping Day. Tomb-Sweeping Day is also called Ghost Festival, Ghost Festival, Tomb-Sweeping Day, Missing Family and Death Festival. Tomb-Sweeping Day is one of the twenty-four solar terms in China lunar calendar, after the vernal equinox and before Grain Rain.

Tomb-Sweeping Day is a traditional festival in China, and it is also the most important festival to worship ancestors and sweep graves. Grave-sweeping is commonly known as going to the grave and offering sacrifices to the dead. At the same time, Qingming is one of the 24 solar terms in China. Because the 24 solar terms objectively reflect the changes of temperature, rainfall and phenology throughout the year, ancient working people used them to arrange agricultural activities.