What does the lunar leap month mean? What determines leap month?

A leap month is a way to set a leap month in a calendar. In China, leap month refers to the month added to every leap year in the lunar calendar. In order to coordinate the contradiction between the tropic year and the Han calendar year and prevent the lunar year and tropic year from being out of touch with the four seasons, 1 leap is set every two to three years. In ancient times, 19 leap week was used, but in the Linde calendar of the Tang Dynasty, the fixed leap week was abolished and the unseasonable month was adopted.

Leap months are arranged according to the full moon, that is, the full moon. The length of a moon is 29.5306 days, which is the cycle of the moon's profit and loss. According to the provisions of the lunar calendar, there are 30 days in the big moon and 29 days in the small moon, and a year is 12 months ***354.672 days. The month of leap month has no seasonal significance.

These twelve moons constitute the Han calendar year, with a length of 29.5306× 12=354.3672 days, which is less than the tropical year's 365.2422 days 10.88 days (that is, nearly 1 1 day), with a monthly decrease of 0.9/kloc.

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In the early years of Emperor Wu of the Han Dynasty, Emperor Wu discovered the previous Zhuan Xu calendar, which began in Jianhai (no longer applicable). Sima Qian was appointed as Taishiling, and more than 20 people, including Sun Qing, Hu Sui, Li Guan, Luo and astronomers, reformed the calendar. With the joint efforts of these experts, after repeated calculations and choices, the new calendar "taichu calendar" was finally promulgated in May this year.

Taichu calendar corrected the month to be the first year (October was the first year of Qin Dynasty), with 29.53 days in January and 354.36 days in a year. This was the most advanced calendar in the world at that time, and it was also the first great reform in China's history.

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