What about the 18 days before the founding of the fourth party?

The algorithm for the first 18 days is as follows

Beginning of spring, beginning of winter, Changxia, beginning of autumn, 18 days ago, indicating the king of the earth. The earth king is a supplement to the twenty-four solar terms. According to the five elements, wood, water, fire and gold are based on each other for the time being, and there is no literature on soil for the time being. Therefore, in every four seasons, there are 18 days designated as belonging to the soil, and the whole year is 72 days. It's called the king of the earth these days.

Wood, water, fire and gold are reduced by 18 days every quarter, leaving about 73 days, thus successfully dividing the whole year into five parts.

This is the "local emperor" in Hakka folklore.

During this time, you can't break ground to build a house, or start work on the wall, and so on.