What are the first three days and the last four days in Tomb-Sweeping Day?

Tomb-Sweeping Day refers to the first three days, the last four days and the last four days in Tomb-Sweeping Day.

The so-called first three and then four, that is to say, you can go to the grave for sacrifice in the first three days and the last four days of Qingming.

In fact, the custom of worshipping ancestors and sweeping graves in Tomb-Sweeping Day did not exist from the beginning. In the Western Han Dynasty, Qingming first appeared in the form of solar terms. At that time, Qingming was just a solar term, and there was no custom of ancestor worship. During the Wei, Jin, Southern and Northern Dynasties, the Cold Food Festival became popular, and our present Tomb-Sweeping Day is also inseparable from the custom of the Cold Food Festival.