Do leap months have the first and twelfth months?

Of course, leap month also includes the first month and the twelfth month.

The appearance of leap month is the result of ingenious arrangement of China lunar calendar to adapt to seasonal changes. In the lunar calendar, the calendar month is based on the change period of Wang Shuo's moon (the time when the moon presents the same phase twice in a row), with an average length of 29.5306 days. Therefore, the lunar calendar has 30 days for the big month and 29 days for the small month, and the whole year is 12 months, and there are only 354 days or 355 days in a year, which is different from the solar calendar year by 1 1 day. So there will be a difference of 1 month after two or three years. If it is not adjusted, as time goes by, the month will be reversed with the hot and cold days, and the calendar will lose its practical significance.

In order to keep the lunar calendar in sync with the Tropic of Cancer, the ancients adopted the method of setting leap months to solve this contradiction. The current lunar calendar method is "seven leap years in nineteen years", because the length of 19 tropic year is basically equal to 19 lunar year plus the total length of seven leap months, so 1 month should be added every two to three years, and the added month is called leap month. Therefore, the lunar leap year has 13 months. According to the calendar rules, the lunar leap month is set to repeat the same month from February to a certain month of 10, and the repeated month is a leap month.

The upcoming Lunar New Year corresponds to the Gregorian calendar date of 65438+2006129 October to 65438+7 February 2007, with 385 days in the whole year. According to experts' calculation, from 22 1 year BC to 2 100 AD, there were only 12 leap years with 385 days, and the last time occurred in 1944.