Why is Qingming 4.4 this year?

Good question. Isn't April 5th Tomb-Sweeping Day? Why is it April 4 this year? Zhao Shu, a folklorist and vice chairman of China Folk Writers Association, said in an interview that Tomb-Sweeping Day was one day ahead of schedule this year because of the leap year.

Zhao Shu said that China was an agricultural country in ancient times. In order to cooperate with agricultural production, solar terms were recorded in the book Shangshu as early as the Spring and Autumn Period. There is a complete record of 24 solar terms in Huainanzi written by Liu An in the Western Han Dynasty. In ancient China, the lunar calendar was used to record time, and the solar calendar was used to divide the 24 solar terms into spring, summer, autumn and winter. Our ancestors called five days 1, and three days were called solar terms. The whole year was divided into 72 days out of 24 solar terms.

24 solar terms is divided according to the position of the sun on the ecliptic (that is, the earth's orbit around the sun). Depending on the sun starting from the vernal equinox (longitude zero, at this moment the sun shines vertically on the equator), every advance of 15 degrees is a solar term; After a week's operation, I returned to the vernal equinox, which is a tropical year with 360 degrees, so it is divided into 24 solar terms. Generally, 15 days after the vernal equinox is called Qingming.

Last year, it was April 5th 12: 52 in Tomb-Sweeping Day, and this year, it was 365 days, 5 hours, 5 1 minute in Tomb-Sweeping Day, so it fell on April 4th 18: 43, so Tomb-Sweeping Day fell on April 4th.

Zhao Shu said, in fact, you don't need to know that it is so complicated, just remember that every Gregorian calendar is an average year, that is, there are only 28 days in February and Tomb-Sweeping Day is on April 5; In leap years, there are 29 days in February and April 4th in Tomb-Sweeping Day.