Why don't the main branches of the lunar month start from the first day?

The moon column is represented by the branches of the lunar calendar, which festival the month of birth belongs to, that is, the branches of that month are used as my moon column. The month before handover is last month, and the month after handover is next month. Therefore, although both of them were born within one month, the arrangement of the moon columns is different because of the differences before and after the reunification. The dividing point between the month and the month is divided by the festival time, which is different from what we usually call the lunar month.

Beginning of autumn July Festival Bailu August Festival Cold Dew September Festival

In early winter, there is1day heavy snow in1month and1day slight cold in 12 days.

Heavy snow time 2065438+07:16: 32: 35 February 7.

Lunar calendar 2065438+20071October 20th.

In other words, the moon column starting at 6:32 (heavy snow) on the 20th of the lunar calendar 1 1 is considered as a month.