What do you think of running in February?

Leap February, that is, the lunar calendar has two February in a year, and the second February is leap February. This is done to prevent the lunar year from being out of touch with the tropic year (that is, the four seasons).

Leap February appears because the month after February of the lunar calendar only has the solar term "Qingming", and the neutral "Grain Rain" after Qingming falls to the next month. Therefore, the month without neutral gas appears after February. Therefore, the neutral month after February is named "leap February" after February, which is the reason for leap February. It should be pointed out that the setting of lunar leap month is completely an artificial measure to adapt to the laws of nature.

The appearance of leap February:

Through long-term practice, our ancestors divided a year into 24 solar terms, which were placed in 12 months, and each month had two fixed solar terms: the former was called "solar term" and the latter was called "neutral gas". For example, when it rains in beginning of spring and the first month, the former is solar terms and the latter is neutral. Solar terms and neutral gas are alternately arranged in monthly order. The average interval between two adjacent solar terms and neutral gas is 30.5 days. However, a month in the lunar calendar (the first month of the lunar calendar) has an average of only 29.5 days.

In this way, next month's solar terms or gas will be delayed by one or two days compared with the previous month's solar terms or gas. At a certain time, "Zhongqi" was not in the middle of the month, and then moved to the end of the month. There will be only one "solar term" next month, and there will be no "neutral gas". Therefore, according to the lunar calendar, any month with only solar terms and no neutral atmosphere can not be regarded as a month independently, but only as a subsidiary month (sub-month) of a month, which is a leap month.