1, Tomb-Sweeping Day, also known as "outing festival", "outing festival", "March festival" and "ancestor worship festival". The solar term is 105 days after the winter solstice and 15 days after the vernal equinox, generally around April 5 of the Gregorian calendar. It originated from ancient ancestors' belief and custom of spring ceremony, and it is also a natural solar term, which is called the four traditional festivals in China together with Spring Festival, Dragon Boat Festival and Mid-Autumn Festival.
2. The traditional custom of sweeping graves in Tomb-Sweeping Day, China began in the Zhou Dynasty and has a history of more than 2,500 years. However, in the Tang Dynasty, the custom of sweeping graves was attributed to the Five Rites by the imperial court, and it was scheduled for the Cold Food Festival the day before in Tomb-Sweeping Day. During the Song and Yuan Dynasties, Tomb-Sweeping Day gradually replaced the position of Cold Food Festival, and integrated the activities of swinging and hiking in Shangsi Festival, forming a traditional festival centered on ancestor worship and grave sweeping.