How is the leap month arranged?
Leap Moon: This is a rare leap month. /kloc-there was no leap first month from the 8th century to the 22nd century, and there was no leap first month in the 25th and 28th-4th1century. The last leap month appeared in 1640 (the year of Chen Geng) in the 7th century, and the next leap month will appear in 2262 (the year of Nonyin) in the 23rd century. The year of leap January must be the earliest year of Spring Festival.
Lunar leap: It is the rarest leap month among all leap months. From17th century to 33rd century, there was no leap twelfth lunar month (but it was not static, and then the frequency of leap twelfth lunar month would gradually increase from the lowest over time). In the following 36th-38th century, 4th1-47th century and 49th century, there was no lunar leap. The last leap twelfth lunar month appeared in16th century 1574 (Xu Jianian). The next leap twelfth lunar month appeared in 3358 (Wuwu year) in the 34th century.
Note: there is no leap month in 1889, and there is no leap month in 2500 10, 289 1 40831February.
Extended data:
There are two kinds of solar terms. The ancient calendar used constant gas, that is, a year was divided into 24 equal parts by time, and each solar term exceeded 15 days on average, so it was also called flat gas. According to the position of the earth in orbit, the period is 360 and the interval between two solar terms is 15.
Because the earth is near the perihelion during the winter solstice, and the movement speed is relatively fast, the sun travels on the ecliptic for less than 15 days. From summer to around, the situation is just the opposite. The sun moves slowly on the ecliptic, and a solar term reaches 16 days. When using fixed air, it can be guaranteed that the spring and autumn can be divided into two days under the condition of equal day and night.
Because the average length of the two solar terms is about 30.5 days, and the average lunar month is only about 29.5 days, the date of each solar term will inevitably be delayed by 1-2 days from the previous month. If this goes on, there will always be a month when there is only solar terms and no gas. This month is designated as "leap month" and is regarded as1March of the lunar calendar.
Since solar terms appear repeatedly in strict accordance with the length of the tropic year, setting leap months in accordance with the above provisions will inevitably ensure that the average length of the lunar year is very close to the tropic year. 19 Seven-leap Method is how to set leap.
Due to the constant gas method, the average length of a festival in winter is about 29.74 days, which is not much longer than the first month of the lunar calendar, and the solar terms are slowly delayed month by month, so it is very unlikely to set up a leap month in winter.
On the contrary, the earth moves slowly near the summer solstice, and the solar terms are also slow, as much as 16 days at a time. Therefore, there are more leap months in summer and the months before and after, such as the third, fourth, fifth, sixth and July of the lunar calendar, and there will be lunar leap months in the 200 years from 182 1 to 2020. Among them, there is no leap in the first month, winter month and twelfth month, and the leap is the most in May, reaching 16 times.
In the more than 1,700 years from 1640 to 3358, there are six leap years in the first month, namely:1640 2262 2357 2520 2539 2634.
Baidu encyclopedia-leap year and twelfth lunar month
Baidu encyclopedia-first month leap