How to calculate leap month?
2. The law of lunar leap year is one leap in three years, two leap in five years, and seven leap in 19. According to the laws of the lunar calendar, it is mainly determined according to the coincidence with the 24 solar terms of the lunar calendar. Usually, a month with only one solar term (usually a small month) is set as a leap month to make up for it.
1, leap month, is a way of calendar leap. In Asia (especially in China), leap month refers to one month added every leap year in the Chinese calendar (also known as the lunar calendar) (in order to coordinate the contradiction between the tropic year and the Chinese calendar, and prevent the month of the Chinese calendar from being out of touch with the tropic year and the four seasons, 1 leap is set every two to three years.
2. In ancient times, 19 adopted the leap week of 7 leap years. By the time of Linde calendar in Tang Dynasty, the fixed leap week was abolished and the month without season was adopted, so it was leap time. Sometimes leap month also refers to the month that contains leap day in leap year of Gregorian calendar (that is, February of leap year of Gregorian calendar).
If you don't pay attention, probably many people think that "leap month" and "leap year" are the same meaning, but they are not. Although there is only one word missing, the meaning is quite different.
The leap year with 365 days in a year is actually a rough figure, and the exact figure should be 365.422 days. Then 365 days a year is 0.2422 days less than the actual year, and then four years later it is nearly one day less than the actual year.
In order to make up for this difference, the calendar stipulates that four years is a leap year, that is, a year divisible by four is a leap year. In addition, it is stipulated that every century year (the year with two zeros at the end) must be divisible by 400 to be a leap year, and other hundred years are not leap years, that is, "there is no leap in a hundred years."