The first month is also called Meng Chun, Duanyue and Kainian. But in ancient times, the first month did not refer to the first month of the year in the summer calendar. In the summer calendar, the month is the first month, in the lunar calendar, the ugly month is the first month, and in the weekly calendar, the sword month is the first month. Since Emperor Wu of the Han Dynasty, it only refers to the first month of the year in the summer calendar. "Spring and Autumn Period, Hidden Year": "The first year, spring, the first month of Wang." Du pre-note: "The first year of seclusion is also the first month.
Extended data:
The first day of the first month is what we call "Spring Festival" and is called "New Year's Day". "Yuan" is the beginning and "Dan" is the morning. The first day of the first lunar month is the traditional Spring Festival for many ethnic groups, such as the Han nationality in China.
The lunar calendar is a lunar calendar, and the two first months are different. The first month of the lunar calendar starts from the first day, while the first month of the solar calendar (solar terms) in the summer calendar, that is, the first day of silver moon, starts from the second day after beginning of spring, which is about 24 solar terms, and construction starts in December. The earliest first month was solar term correction. Therefore, the earliest January is the first month of the solar calendar (solar calendar), and the summer calendar (base point) in the calendar revision starts from beginning of spring Day.
References:
The first month (the first month of China lunar calendar) Baidu Encyclopedia