In what year does leap month occur?

Lunar leap month is once every three years, twice every five years, and 19 years is seven times.

In the China lunar calendar, 24 solar terms are divided into 12 solar terms and 12 neutral terms. The lunar calendar takes the moon as the cycle (lunar calendar), and the December calendar is about 354 days in total. Combined with the almanac (solar calendar), the almanac is compiled according to the four-season cycle formed by the revolution of the earth. The monthly calendar is shorter than the annual calendar by 1 1 day. Therefore, it is necessary to add 7 leap months every 19 years to make up for the error.

Taking 2006 as an example, July of the lunar calendar happened to be a month with solar terms but no neutral atmosphere, so there was an adjustment error in July. The date of the twenty-four solar terms of the lunar calendar is postponed month by month, so in some lunar months, the gas falls at the end of the month, and it will be out of gas next month. Generally, there will be a month without gas every two years, which coincides with the year when leap months are needed. Therefore, the lunar calendar stipulates that non-neutral months are leap months.

Extended data

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.

There were leap weeks in ancient times, and 19 had seven leaps. In the Linde calendar of Tang Dynasty, the fixed leap week was abolished and the neutral moon was adopted, so it was leap time. Sometimes leap month also refers to the month that includes leap day in leap year of Gregorian calendar (especially in February of leap year of Gregorian calendar).

Baidu encyclopedia-leap month

China News Network-once-in-a-century calendar phenomenon: the leap year in Gregorian calendar coincides with the leap month in lunar calendar.