Conventional calculation of lunar calendar

The calculation of solar terms and the time of the first lunar month shall be based on East longitude 120 degrees and China Standard Time.

According to the Purple Mountain Observatory of Chinese Academy of Sciences, the longitude of the Yellow River is the coordinate value used to determine the position of celestial bodies on the celestial sphere in the ecliptic coordinate system. In this system, the celestial sphere is divided into two hemispheres by the ecliptic plane. The sun runs to longitude 0 for the vernal equinox, to longitude 90 for the summer solstice, to180 for the autumn equinox, and to 270 for the winter solstice.

Shuori: The day when the moon moves between the earth and the sun is called Shuori.

Pingshuo: calculated by the average length of the moon, regardless of the inequality between the sun and the moon; Disadvantages: "The day containing the real" new moon "may sometimes appear on the last day of the previous month ("dark day ",29th or 30th), and sometimes on the second day of junior high school".

Deciding the new moon: the inequality between the sun and the moon is taken into account in the calculation, and the day of the real "new moon" is taken as the beginning of each month.

Homogeneous level: the uneven motion of the sun on the ecliptic is not considered in the calculation, and the first anniversary (tropic year) is divided into 24 solar terms, and the average number of days between the two solar terms is 15.22 days.

Fixed Qi: Considering the uneven movement of the sun on the ecliptic, the days between the two solar terms of fixed Qi are different, the short one is only 14 days, and the long one is 16 days.

Winter solstice: the day when the winter solstice is handed over is called winter solstice. The winter solstice must be in the second month: set the day of the winter solstice or the day before the winter solstice as the "starting point" of the first day of the second month (note: the starting point is different from fortune telling).

Jian Zheng: In the first month of the year, the establishment of the lunar calendar is "Xia Zheng": the first month of establishing the summer calendar [the second month is 1 1 month];

Andrew: The first month of the lunar calendar is ugly [February and December], and the Lu calendar is the same as the lunar calendar;

Zhou Zheng: The Zhou calendar (Zhou Dynasty calendar) was built in the first month [February is the first month];

Qin Zheng: The Zhuan Xu calendar in Qin Dynasty was established in the first month, and October in Shanghai is the first month of the year.

Solar terms: A year is divided into twelve seasons, twelve middle qi and twenty-four solar terms. The constitutional calendar of the Qing Dynasty (A.D. 1645) was marked with flat gas before, and the constitutional calendar of the Qing Dynasty (A.D. 1645) was marked with fixed gas after. Pay attention to the difference between annotation and calculation. The algorithm of determining the moon's sky was produced in Sui and Tang Dynasties, but it was blocked by conservative forces at that time and did not complete the transformation from flat sky annotation to fixed sky annotation. For example, when the monk and his party revised the Dayan calendar, they advocated the annotation of the gas, but the court did not adopt his theory. Finally, the fixed space algorithm is only used to calculate the solar eclipse, five-star arrangement and solar eclipse forecast before the end of Ming Dynasty. By the end of the Ming Dynasty, after a fierce debate, the principle of "fixing the atmosphere and paying attention to the calendar" was finally established.

Calendar: it can be divided into solar calendar, lunar calendar and yin-yang calendar;

Gregorian calendar: A year is divided into 12 months, which has nothing to do with the movement of the moon. According to the date of the solar calendar, we can know that the four seasons change from cold to summer, and guide agriculture reasonably. Gregorian calendar (scientific name Gregory calendar) is a kind of solar calendar.

Lunar calendar (lunar calendar): one month is the full and short term of the moon (that is, the new moon equals 29.50588 days), and the product of 12 months is one year. The annual apparent motion law of the sun is completely ignored, so the date of the lunar calendar can't show the warmth and coldness of the four seasons. This calendar has no practical value, except for Islam, which has been abandoned.

Lunar calendar: China lunar calendar belongs to this category. It takes the moon phase, that is, the change cycle of the moon, as the month length and the return year of the sun as the age. By setting leap months, the average calendar year adapts to the tropic year. According to the date of the lunar calendar, we can not only know the ebb and flow of tides, but also grasp the changes of seasons.

Almanac: A publication that records calendars and other related information, such as yellow calendars and perpetual calendars. Electronic almanac is the product of scientific and technological development and a new carrier. Published by Calendar Group of Purple Mountain Observatory of China Academy of Sciences.

1. Calculation is based on Beijing time.

2. The positions of the sun and the moon are calculated according to the simplified standard model of celestial positions recommended by the Basic Astronomy Review Standard Committee under the International Astronomical Union.

The lunar day where the new moon is located is the first month of the lunar calendar.

The lunar month of winter solstice is 1 1 month.

5. If there are 1 1 months from the beginning of a certain year to the next year (excluding), the first lunar month without solar terms will be regarded as a leap month;

6. The second lunar month (excluding leap month) after11is the beginning month of the lunar year.

7. Lunar reference time: The lunar calendar corresponding to the time interval from 0: 00 on February 2, 1984 to 0: 00 on February 20, 1985 on the Gregorian calendar in Beijing time is Jiazi year.

8. Reference time of the main branch of the lunar calendar: Gregorian calendar1984 65438+1October 3 1 The corresponding lunar calendar is Jiazi Day. The ancient definition of Japan is that the earth rotates once a day. When the sun is farthest from the horizon, it is equivalent to 23:00~ 1:00 Beijing time. But in the lunar calendar, a day starts at midnight (0:00), not at midnight (23:00).

Monthly policy and final rule: the new moon is the starting point of each month (the first day); There are as many days as there are from the first day of the first month to the second day. The big moon has 30 days and the small moon has 29 days; Pingshuo was used before the second year of Wude in Tang Dynasty (AD 6 19), and Dingshuo was used after the second year of Wude (AD 6 19).

Year policy and leap setting rules: the winter solstice must be in the second month (1 1 month). If there is1month from the previous winter to the sun and moon (1month) to the next winter to the sun and moon, there is no leap. If there is1month, there is no leap. The first neutral month after the last winter to the sun and the moon is leap month, and the next few months are called leap months. For example, there is 12 months between the winter solstice in Renzi year (2032) and the winter solstice in Guichou year (2033), so there is no leap. There are 13 months from the winter solstice in the year of Guichou (2033) to the winter solstice in the year of Jiayin (2034), and a leap must be set. The first neutral month from the winter of the year of guichou (2033) to the future is the next month of that month, which is designated as leap month. It occurs after 1 1 month, so it is called leap 1 1 month.

1. Chronology of trunk and branch

For example, Jia Zi is the first year, Ugly B is the second year, and Bing Yin is the third year ... Sixty years is a week. Week after week, starting from the year of Jiazi, starting from the week, and starting again and again. Ganzhizhi sprouted in the early Han Dynasty, and in the second year of Emperor Yuanhe of the Han and Yuan Dynasties (AD 85), the court ordered the implementation of Ganzhizhi throughout the country. Since then, the year of the branch calendar and the year of the emperor have been used together in the traditional calendar of China. It is worth noting that the dates of trunks and branches are based on the first day of the first lunar month and the Lunar New Year, while the zodiac signs are changed at the beginning of spring.

Gregorian calendar era number and year of main branch, for example, 1929 is the past year, 1930 is the year of Wu Geng ... and 1989 is the past year. The four years and Gengwu years we see on the calendar are arranged according to the chronology of trunks and branches. It is also worth noting that the year number belongs to the Gregorian calendar, which is subject to the Gregorian New Year (Gregorian calendar 65438+ 10/); The calendar year of cadres and branches belongs to the lunar calendar, which is subject to the Lunar New Year, that is, the first day of the first lunar month every year. This must not be confused. These two calendars are independent systems and are not related to each other. Also, the chronology of cadres and party branches must not be mixed with the Gregorian calendar date, otherwise it is a serious fallacy.

2. Dry branches and the moon

It began in the twelfth lunar month in the pre-Qin period, so we must first determine the geographical branch: take the month where the winter solstice is located as the sub-month, and so on. If it is a leap month, the earthly branch of last month is adopted. After determining the earthly branch, then determine the heavenly stem: if you meet A or your own year, the first month is Bingyin, the second month is Ding Mao, the third month is Chen Wu, and so on; B or Geng Year, the first month is Wuyin; The first month of Year C or Year Xin is Geng Yin, the first month of Year Ding Nian or Year Ren is Ren Yin, and the first month of Year E or Year decyl is Jia Yin. The main branch of the first month is known, and the rest months can be inferred in the order of sixty sons. The first day of each month (that is, the first day of a digital calendar month) is the starting point of a calendar month, and the same calendar month is used in leap months. This calendar method has been adopted by officials in past dynasties.

3. anniversary of dry branches

The first day of Jia Zi, the second day of Yi Chou, and the third day of Bing Yin ... 60 days a week. A week later, starting from Jiazi Day, it started again and again. For example, the first day of the first lunar month (20 12) is the day of ghosts and gods, and the second day is the day of Shen Jia ... The first day of March is exactly 60 days, so the second day of March is the day of ghosts and gods, and the third day is Shen Jiari. In the "Han Calendar", the official calendar has never been interrupted, and there is no confusion. It is the longest calendar in China and even the world. With a clearly recorded date, it can reach more than 2700 years.

4. When drying branches

The earthly branches in one day are also certain, so the 24 hours of the twelve earthly branches are at night 1 1 point to 1 point, 1 point to 3 o'clock is ugly, and the rest are pushed. The day is inferred from the day, and its song is as follows:

A has given birth to a, and B, G and C come first.

Bing Xin started in Wu, and was destined to be a boxer.

You can't do it, but you can't.

That is, if the day is A or his own, the child should be accompanied by A when he was a child; If the day is b or g, it should be accompanied by c as c; On the day of Bingxin, Wu was the son of Wu; Ding Renri is a boxer; Pentecost is a seedless day. When you know your child's main branch, you can infer the rest.

It is worth noting that the birth date algorithm used in traditional folklore is different from the trunk and branch of calendar. In the four columns, the annual column of dry branches uses the node time of beginning of spring, and the monthly column of dry branches uses the node time of beginning of spring, Jingzhe, Qingming, Changxia, Mangzhong, Xiaoshu, beginning of autumn, Bailu, Hanlu, beginning of winter, Daxue and Xiaohan. Note that it is not 0 o'clock on Boxing Day, and a main and branch sun column can be used.