When is the twelfth month?

Question 1: In China, the leap month is very unlucky. That was before 1645, and we won't have a chance to see it for the last time.

Question 2: When will there be a leap month?

In order to keep the return year of the lunar calendar in sync with the Gregorian calendar, the ancients adopted the method of setting leap months.

Definition of year, month and day

Since ancient times, all human activities have been inseparable from time. In order to calculate time, we must introduce time units. All human activities are carried out on the stage of the earth, so the phenomenon of alternating day and night and changing seasons is naturally regarded as the most basic unit of time.

The rotation of the earth has brought us the first natural unit of time, which is the sun. The earth rotates once a day on its axis, which is a cycle of alternating day and night. The revolution of the earth around the sun brings the second unit of time, which is the year. The whole revolution of the earth is a four-season cycle. Finally, the movement of the moon around the earth established the third time unit month for us.

Any movement is relative, and the movement of celestial bodies is no exception. Whether it is the rotation, revolution of the earth or the movement of the moon, it is necessary to observe it relative to some reference points. So there are different years, months and days in astronomy because the reference points used are different. The days we use in our life are equal in length, which is called flat sun day. Flat solar day is no longer a natural time unit, but the time when the earth rotates once relative to the sun when its orbit is a perfect circle and its axis of rotation is perpendicular to the plane of the orbit. The time period that determines the change of the four seasons is called tropic year, and its length is equal to 365.422 flat solar days. Finally, the cycle of the moon is called the new moon, and its length is equal to 29.5306 flat solar days. Obviously, the length of years and months is not an integer multiple of days, which brings some troubles to the timing problem in daily life. How to calculate time with three units of year, month and day is called calendar, including the number of days in a year, how to determine the number of days in different months of a year, and the law of leap.

Question 3: Once every few years, the lunar calendar has been used for a long time in China, also known as the summer calendar. It was once demoted as an "abandoned calendar". The last revision was in the seventh year of Qing Qianlong (about

1742), which was determined by Zai Jinxian's revision of Tang Ruowang's "constitutional calendar". Farmers in China are very familiar with the lunar calendar.

As we all know, many folk festivals are based on the lunar calendar. Among the 24 solar terms, the new moon, the new moon and the twelfth birthday are also widely popular in the lunar calendar.

Xiao and other lunar calendar are less 1 1 day each year than the solar calendar, and 33 days less in three years. Therefore, every three years plus one month is called leap month. But for three years.

There are still three or four days left in a leap, which is still inaccurate. So the method of two jumps in five years was adopted. But in five years, I made two leaps and added four or five days. So it took eight years.

Three leap to remedy, but eight years three leap less than two days. After repeated observation and practical test of astronomical phenomena, the seven-year leap of 19 was finally determined.

There are 7 leap months between 65438 and 09. Gregorian calendar 19 is 6939. 18 days, and lunar calendar 19 (including 7 leap months) is 6939.438+0.

Day, so the difference between the two calendars is only about 2 hours, which can be said to be more accurate. It should also be pointed out that in ancient China

Zu Chongzhi, a contemporary scientist, creatively put forward the leap method of setting 39 1 year 144 leap month, which is more accurate.

Therefore, the lunar year is sometimes twelve months and sometimes thirteen months. This is not chaos, but strictness.

Scientific and formal. However, which month of the year is a leap month? The position of the lunar leap month is different in history.

Working on it. Generally speaking, before the early Western Han Dynasty, the leap month was placed at the end of the year. For example, in the early Han Dynasty, September was regarded as a year.

The last month of September, when the leap month was placed after September, was called "post-September". Later, with the gradual progress of the calendar,

Accuracy also stipulates the placement method of leap month, that is, the month without neutral gas is regarded as leap month. This set of leap rules

It is still in use today. So here is a special introduction to China Automobile.

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Zhongqi is a part of the 24 solar terms. The 24 solar terms are actually a reflection of the apparent motion of the sun, but the reality is that

In essence, the ecliptic is divided into 24 equal parts, and the unequal parts should account for 15 degrees of the ecliptic. Therefore, each month contains two solar terms. This is in ancient times.

The generation is collectively referred to as "Qi". Later, people called the front "solar terms" and the back "neutral gas". Due to two solar terms or

The average number of days between the two neutral gases is 365.2422/ 12=30.4368, while the first month of the lunar calendar is 29.5306, which is almost the same.

A day's difference. Therefore, the date of the lunar month is delayed by nearly one day every month. If this situation continues, it will

But in some months, the gas falls on the last day of this month, so there will be no gas next month, but it will happen in

Early next month. Because every month has its own fixed neutral atmosphere, then the month without neutral atmosphere is called leap month.

This is natural. Of course, after complicated calculation, the arrangement of leap month can be determined in detail. The following table lists the slave 1949.

Distribution of leap months in 2020.

A.D. 1949-2020 Lunar Leap Month Table

1949 leap July 1952 leap may 1955 leap March 1957 leap August 1960 leap June.

1963 leap April 1966 leap March 1968 leap July 197 1 leap may 1974 leap April.

1976 leap August 1979 leap June 1982 leap April 1984 leap October 1987 leap June.

1990 leap may 1993 leap March 1995 leap August 1998 leap may 200 1 leap April.

Leap in February 2004, leap in July 2006, leap in May 20 12, leap in April 20 14, leap in September.

20 17 leap in June 2020 leap in April.

As can be seen from the above table, there are more leap months in April, May and June, and fewer leap months in September and 10, especially in 1 1 February.

January and the first month. Why is this? It turns out that the time interval between the two gases is different. As mentioned earlier.

30.4368 days is just an average. In fact, the earth's orbit around the sun is an ellipse, and the sun is located on one of the ellipses.

Focus. The farthest point on the orbit from the sun is called perihelion, and the nearest point is called perihelion. The earth is far away.

If the movement near the sun point is slow, the time interval between two neutralizations will be very long, up to 3 1.45 days, so there is no possibility of neutralization.

Many, ... >>

Question 4: Inventory: In the history, when did the leap twelfth lunar month fail to run the twelfth lunar month and the first lunar month? This is a rule on the calendar. If the twelfth lunar month or the first lunar month is counted by time, it can be solved one month in advance or later.

Question 5: When does the lunar calendar leap to December? 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, reaching as many as 16 days at a time. Therefore, there are many leap months in summer and the months around it, such as March, April, May, June and July in the lunar calendar. There are 74 leap months in 200 years from 182 1 to 2020. Among them, 1 month, 1 1 month and1February have no leap, and the most leap is in May, reaching 16 times. Another calculation shows that there will be another leap month in 2262; Leap1February will first appear in 3358.

Question 6: What year is the twelfth lunar month leap? Last year was a leap December.

Question 7: leap years in the Gregorian calendar are judged according to the following rules: leap every four years, not leap in a hundred years, and leap again in four hundred years.

Simple calculation method of leap year in Gregorian calendar: (A year that meets one of the following conditions is a leap year)

1。 Divisible by 4, but not by 100. (For example, 2004 is a leap year, but 1900 is not)

2。 Divisible by 400. (For example, 2000 is a leap year)

The twelfth lunar month is 65438+ February.

Question 8: What year is Lunar Leap 65438+ February? In China's calendar, there are neither leap months nor leap months.

Question 9: There will be no wet lunar month in December, at least once in a thousand years.

In fact, we haven't had a "leap twelfth lunar month" for more than two thousand years. This is just a common phrase. Then, why do we never meet in real life, but often talk about it among the people?

Many calendars have been used in the history of China, such as the summer calendar, the lunar calendar, the weekly calendar and the Zhuan Xu calendar used in the Qin Dynasty. Every January, all kinds of legislation are different, only the summer calendar is consistent with our current month, and the first month is the first month of each year. The above four calendars were used in Xia, Shang, Zhou, Qin and early Han dynasties in China. They all regard the period 1 of the moon's orbit around the earth as 1 month, which is shorter than the time of the sun's orbit around the earth, that is, the tropical year. In order to make the time of 24 solar terms consistent with the natural year, the remaining time is accumulated to 1 month, 65433. The month added in leap year is called leap month, which must be a month without neutral atmosphere in a year. The neutral atmosphere is 12 of the 24 solar terms, such as winter solstice, severe cold, rain, vernal equinox, Grain Rain, Xiaoman, summer solstice, summer solstice, summer equinox, first frost and light snow (while the remaining 12 solar terms are not called neutral atmosphere). A month plus a leap month is called a leap month. For example, if the month after August of 1976 is a leap August, the month does not include any of the above "neutral gases". In this way, every 19 year of the lunar calendar coincides with the tropic year on which the solar calendar is based, and also coincides with the distribution of the 24 solar terms.

In order to further understand the "leap twelfth lunar month", I consulted various almanac and materials, especially the year 200 included in the new practical calendar (1 1 March 2nd edition, 20 1 1 printed on March 5th). In these 200 years, there are 73 leap years, that is to say, there are 73 leap months, including 8 in February, 8 in March, 4 in April 14, 5 in May 14, 6 in June 12, 8 in July and 6 in August. There are only 65438+ October and 65438+ February, that is, there are no leap months in the first month and the twelfth month, so where did the "leap twelfth month" come from?

In fact, the statistics themselves do not show the leap of the twelfth lunar month. We need to combine the past with the present. Except that the month of the summer calendar is exactly the same as our current month, other calendars take 65438+ February, 165438+ October and 65438+ October as the first month of the year, so today's 165438+ October and September are equivalent to respectively. In this way, no matter which of these three calendars has leap months-although there is only one difference in 200 years! However, in any case, there are always people who can wait and expect. Probably because of this, the folks have the saying that "there is a twelfth lunar month every thirty years". In this way, whether it is three years or thirty years, it only means a permanent and long-term nature in time, not a specific length of time.

Taichu calendar has been used in China since the first year of Emperor Wu of the Han Dynasty. The calendar basically follows the summer calendar and has remained unchanged for more than two thousand years. Although there were several dynasties' revisions during the period, only some deviations were corrected and some "fine-tuning" was made. Because China's Chinese nation and China system were really formed in the Western Han Dynasty. The Zhuan Xu calendar of the Qin Dynasty in the early Han Dynasty has still been used for more than 100 years. It can be imagined that in a period of time after the promulgation of the new calendar by Emperor Wu of the Han Dynasty, there was probably a period of alternation between the old and new calendars, especially in the era of extremely underdeveloped information. This alternating period will be longer, because the leap September in the summer calendar is also the leap December in the Zhuan Xu calendar, so people naturally call the leap September in the new calendar the old calendar.