It is said that the lunar calendar sometimes has an extra month? Why do you want to look at the calendar? Why didn't 65438+ March come out? I've seen too much. Are there two September? Brother and sis

It is said that the lunar calendar sometimes has an extra month? Why do you want to look at the calendar? Why didn't 65438+ March come out? I've seen too much. Are there two September? Brother and sister. Yes! That refers to the lunar calendar, called leap month. Agricultural proverbs have two leaps in three years and three leaps in five years. The main reason is that the Gregorian calendar is based on the earth's rotation around the sun for 365 days a year, while the lunar calendar is based on the calculation of the moon from round to dark. The difference between the two calendars is made up by the leap month of the lunar calendar. That algorithm is a bit complicated, and I don't know much about it, but that's about it.