How to calculate leap month?

What month is the lunar leap month? It depends on the 24 solar terms in a year.

In the China lunar calendar, 24 solar terms are divided into 12 solar terms and 12 neutral terms.

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.

For example, April 29th of the 200 1 lunar calendar is full of breath, and the first day of every other month is the solstice of the next summer. If there is no gas this month, it will be a leap month, after April, so it is called leap April.