Is there a specific date in Tomb-Sweeping Day? Why are some years April 4th and some years April 5th? Is it the only way to read almanac?

According to the solar terms, fifteen days after the vernal equinox; According to the Gregorian calendar, April 5th every year and leap year is April 4th.

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. "