Since the lunar leap month is to find a month without gas, then this year's lunar summer is already full of gas, why leap?

Because we should go hand in hand with the 24 solar terms and use them to guide agricultural production.

China's traditional calendar emphasizes the calculation of day order and month order, as well as big month, small month, normal year and leap year. The state has set up special institutions to calculate calendars.

There are three calendars in the world: one is the solar calendar, which means that the time for the earth to make a circle around the sun is one year, and the number of months and days in a year can be specified artificially; One is the lunar calendar, in which the time for the moon to circle the earth is one month, and only a few months in a year can be designated artificially;

The third is the lunar calendar, that is, the average time for the moon to go around the earth is January, but by setting leap months, the average number of days in a year is equal to the average time for the earth to go around the sun, such as the Chinese calendar and Tibetan calendar. So China's Han calendar is not a lunar calendar, but a yin-yang calendar. The lunar calendar and the solar calendar in the Han calendar have their own uses. The lunar calendar can indicate the moon's profit and loss, and can also predict the tides.