Leap months occur every few years.

Once every 2-3 years. Leaping month is a way of calendar leap. In Asia (especially China), leap month refers to the month that is added every two to three years in the lunar calendar. In order to coordinate the contradiction between the tropic year and the lunar year and prevent the lunar year from being out of touch with the tropic year, that is, the four seasons, 1 leap is set every two to three years.

Leap months occur every few years.

The so-called leap month means that one month is added every two to three years in the lunar calendar, which is a way to set up leap in the calendar. The reason why there are leap months is that the number of days in the lunar year is sometimes one month different from that in the solar year; In order to coordinate the number of days between the lunar year and the solar year, the lunar calendar adopts the "leap method" to adapt to the total number of days in these two years.

The current lunar calendar method is "seven leaps in nineteen years", that is, every two to three years, a lunar month that is the same as the previous month must be added, and the added month is called a leap month. The rules of leap method are based on 24 solar terms related to the tropic year of solar calendar. A tropical year is divided into 24 solar terms. If the twenty-four solar terms are discharged from beginning of spring to severe cold, then odd numbers are called solar terms and even numbers are called qi.

In the lunar calendar, twelve Chinese qi are used to represent twelve months of a year, and the average interval between Chinese qi and Chinese qi will be nearly one day longer than that of a lunar month. In the long run, there will always be a phenomenon of gas neutrality at the end of the month, so there will be no gas next month, only solar terms. So this lunar month without neutrality is called the leap month of last month.