There is a popular saying here that "my uncle died in the first month", which is quite taboo. I remember one year, my father cut his head without looking at the calendar in the first month. My grandmother saw it and scolded my father badly, but my father and his uncle were both healthy and that year was safe.
Later, when I saw the records in the Book of Rites, I realized that the original meaning of "dead uncle" was "homesickness". When the Qing dynasty entered the customs, in order to protect the Central Plains, Chinese people were required to shave their heads and leave braids in the middle, which caused dissatisfaction among Chinese people. Therefore, some people use "no haircut in the first month" to express their yearning for the former dynasty, which is actually "homesickness." In order to hide people's eyes and ears, the false report is "dead uncle", which has been passed down to this day.
Generally speaking, if there is a folk custom that you can't cut your hair in the first month, try not to cut it, so as not to cause many family conflicts for such a trivial matter. If you cut it in the first month, something will happen to your uncle, and his family will not treat you as a sinner forever. Then jumping into the Yellow River can't be washed away, which is meaningless to ignorant people. Therefore, for some old customs, you can only say "respect" appropriately, and so on.