How do we calculate the lunar calendar for the Spring Festival?

The lunar calendar in our country is the lunar calendar. Is to consider the movement of the sun and the moon at the same time. Among them, 24 solar terms return completely according to the sun. Therefore, the solar calendar date of each solar term is basically certain, while the lunar calendar date is far apart. But the lunar calendar is based on the monthly moon profit and loss. As we all know, the first day is always a new moon, looking forward to the fifteenth.

In the China lunar calendar, the beginning of a year is actually the beginning of spring. When we say "Xu Bing Year" and "Jiazi Year", we should start from beginning of spring. This is the calculation of "time horoscope". Many people in China don't know this. But beginning of spring has nothing to do with the moon phase. The lunar month must start from the first day, that is, from the new moon. Therefore, the new moon closest to beginning of spring is considered as the first day of the first month, that is, the Spring Festival. But this day is sometimes before beginning of spring and sometimes after beginning of spring. This is why there are often leap months in the lunar calendar.