How did the lunar calendar in China come about?
Some people may ask that the lunar calendar prefers the moon and loses the sun, which makes the days out of touch with the seasons, but the solar calendar only cares about the sun and ignores the moon, which makes the month meaningless. Can you find a way to "kill two birds with one stone", so that a calendar can take care of the relationship between seasons and make the first day of a month always fall on the first day of the month?
Of course, this comprehensive calendar is neither a lunar calendar nor a solar calendar. Scientists call it "the lunar calendar". The lunar calendar used in the history of China is one of the best representatives of this kind of lunar calendar. The lunar calendar is also called summer calendar, middle calendar and old calendar. People in our country have always called it "Lunar Calendar" inappropriately, which is easily confused with the abbreviation of "Lunar Calendar". In fact, there are differences between the two in principle. The lunar calendar in China is generally in season and can guide agricultural production well.
The lunar calendar should observe both the sun and the moon, so that the two can be organically unified. Based on the first month of the lunar calendar, the length of a year varies greatly: a normal year includes 12 months, which is 353 to 355 days long, while a leap year includes 13 months (one more leap month), which can be as long as 383 days or 384 days. The purpose of this is to ensure that the first month to March is spring, April to June is summer, July to September is autumn and October to December is winter.
The moon in the lunar calendar is roughly the length of the moon, so the small moon is 29 days and the big moon is 30 days. In order to ensure that the first day of each month (the first day) must be a new moon (the new moon), the arrangement of large and small months is not fixed and needs to be determined by observation and calculation. So it is common that it is big for two consecutive months, big or small, and sometimes even three or four consecutive months. For example, Gregorian calendar 1 981-1982, that is, Xinyou 1 1 month,1February and Ren Xu1month, three consecutive months are 30-day months, but This is because the length of the first month of the lunar calendar is longer than 29.5 days, and this seemingly unreasonable phenomenon will appear if it is accumulated more.
In order for the lunar calendar to guide agricultural production, it is necessary to make the months conform to the seasons. Therefore, as early as the 3rd century BC, the Zhuan Xu Calendar of the Qin Dynasty put forward the principle of "seven leaps in nineteen years", which was at least 160 years earlier than that of the West. In this way, the average calendar year after the leap month is exactly 365.2502 days, which is roughly the same as that in julian calendar, but two centuries earlier.
Because of the leap month, the first day of the first lunar month (Spring Festival) is always fixed in winter, the earliest is 65438+1October 23rd (such as1993,2012), and the latest is February 20th (such as 1985). It will never be like the Muharram of Islam. Sometimes the New Year is celebrated in winter, and sometimes it is welcomed in summer.
Calendar research plays an extremely important role in ancient astronomy in China. China's calendar has a long history, comparable to that of Egypt and Babylon, and it has been carefully studied, ranking first in the world. According to incomplete statistics, there are more than 100 kinds of calendars put forward in the history of our country, and as many as 94 kinds of calendars have great influence, each with its own characteristics, which quite accurately reflects the motion laws of the moon, the earth and the sun in a certain period. For example, when the "taichu calendar" was implemented in the early years of the Western Han Dynasty, astronomers in China already knew the difference between the new moon and the moon, stipulated the principle of adding leap moon, and calculated the rendezvous period of Venus, Jupiter, Mercury, Mars and Saturn.
Another example is the Northern and Southern Dynasties, when Zu Chongzhi, an astronomer and mathematician in China, discovered a more reasonable method of setting leap months-setting 144 leap months every 39 1 lunar year. In this way, the equivalent length of a year is 365.2428 days, which is only 25 seconds away from the correct tropical year. And the average length of "Da Li Ming" compiled by him in January is 29.53059 days, which is only 1 second away from the length of Wang Shuoyue!
By A.D. 128 1 year, Guo Shoujing, an astronomer in the Yuan Dynasty, had compiled a new almanac with his own instruments, which was first-class in the world at that time. The length of the month in the calendar is 29.530593 days, which is only 0.37 seconds away from the exact value. The length of a year is 365.2425 days, which is exactly the same as the Gregorian calendar used now! But it is 360 years earlier than the Gregorian calendar.
Unfortunately, the lunar calendar in China is too complicated for most people to remember, and it is also difficult to cooperate and communicate with the world. Therefore, after the Revolution of 1911, China began to gradually use the Gregorian calendar (while retaining the lunar calendar). Nowadays, people generally only remember the days of the solar calendar, and the lunar calendar needs to be checked to know.