In the summer calendar, January in spring is the first month, which is equivalent to the lunar month in the dry calendar; In the Shang calendar, December is the first month, which is equivalent to the ugly month in the Ganzhi calendar; The first month of the weekly calendar is winter and November, which is equivalent to the month of Jianzi in the dry calendar; The first month of the Qin calendar is October in winter, which is equivalent to the moon in the dry calendar. This is the origin of Li Xia Yin Jian, Li Shang Jianchou, Li Zhoujianzi and Li Qin Jianhai.

The first month of the lunar year

The first month originally refers to the first month of the solar calendar: Meng Chun is the first month of the summer calendar, which is equivalent to the first month of the official calendar. The earliest first month was "December Construction". Therefore, the earliest January is the first month of the solar calendar, and the establishment of Yin in history began in the beginning of spring. The first month of the lunar calendar.

Later, the relevant month of the lunar calendar was called the first month of the lunar calendar, and the first month of the official calendar was silver moon, including beginning of spring and rainfall in the 24 solar terms. The first lunar month is the first lunar month when the main time in beginning of spring is 15 or 16. If you come late, you should add a lunar month as a leap month in the year before the lunar calendar, otherwise it will not match.

Baidu Encyclopedia-The First Month