What's so particular about the twelfth lunar month haircut?

The twelfth lunar month haircut has the following instructions.

In traditional customs, there is no saying that you can't get a haircut in the twelfth lunar month, so generally speaking, you can get a haircut in the twelfth lunar month. After entering the twelfth lunar month, there are many taboos in geomantic omen, but there is no emphasis on haircut. Just look at the yellow calendar of the day and avoid the conflicting Zodiac Day. In this regard, there are two main points in the yellow calendar. The word haircut refers to shaving the fetal head of a newborn baby or cutting hair and becoming a monk. Now, some old people will have their hair cut according to the dates in the yellow calendar. The arrival of the twelfth lunar month means the alternation of the old and the new. When we enter the twelfth lunar month, the Spring Festival is not far away.

A haircut is more than just cutting off your hair. In fact, we also have certain taboos when choosing a haircut time. For example, if someone in our family dies, once a person learns the bad news, he can't get a haircut or shave for a month or a hundred days. Ewenki people have the custom of banning haircuts and shaving in the afternoon. Hairdressing is forbidden before the seedlings break ground, otherwise the seedlings will not grow.

In our country, there is also a custom that you can't get a haircut in the first month, and you can't get a haircut at your uncle's house, because it is more likely to cause old associations, so it is especially taboo.