Tomb-Sweeping Day is one of the most important festivals in the traditional customs of China. Tomb-Sweeping Day is now a national grave-sweeping festival. According to the solar calendar, it is about April 5, and according to the lunar calendar, it is 15 days after the vernal equinox. According to the saying of "always asking questions", "Everything grows clean and bright at this time. So it is called Qingming. "