How did you count the years and months in ancient times? Please, everyone!

The period from cold to summer is one year, and the length of one year in pre-Qin period is 365.25 days. The period between the full moon and the full moon is a new moon, and the length of a new moon in the pre-Qin period is about 29.53 days. Year, month and day constitute the three basic elements of a calendar. The main task of the calendar is to arrange the three cycles of year, month and day reasonably, and make them into integers, which is convenient for memory and use.

There are three kinds of calendars: one is a solar calendar that only considers the movement of the sun. The earliest people who used the solar calendar may be the ancient Egyptians. According to the flood cycle of the Nile, they set a year as 365 days, divided into 12 months, with 30 days each month. 12 months later, five more days were added, making 365 days. Later, Caesar, the ruler of Rome, inserted these five days into different months, and took two days out of February, which they considered unlucky and inserted into other months. This year has seven months 3 1 day, four months 30 days and a month 28 days. During the Roman period, astronomers had known that a tropical year had 365.25 days. If we just follow this rule, we will miss one day every four years. So they added an extra day in February. A calendar based on the change of moon phases is called the lunar calendar. Not many countries use the lunar calendar now, and only a few Arabs use the "Islamic calendar" according to the lunar calendar method.

China's lunar calendar

China's lunar calendar is the third compiling method, which not only considers the changes of the full and short periods of the moon, but also considers the annual apparent motion of the sun. According to research, China began to use the Yin and Yang calendars in Shang Dynasty.

On average, there are six 30-day months and six 29-day months in the lunar calendar, which add up to 354 days, which is different from the length of 365 days in a year 1 1 day. If this arrangement is always made, there will be an interval of more than one month every three years. So the ancients came up with a way to add one month every three years. This extra month is called leap month. However, it was later discovered that three years plus one month was too little to make up for the 33 days left by three years; Five years plus two leap months is too much, exceeding the difference of five years and 55 days. If you add seven leap months to 19, you can get satisfactory results. The year of 19 is 6939.75. There are 228 months plus 7 leap months in 19 year, which is 235 months. The total number of 235 months is 6939 .55 days, and the difference between the days in 19 year is only 0.2 days, which is less than 5 hours.

The lunar calendar can basically keep the month consistent with the climate, unlike the lunar calendar, even in June, it may snow.

The 24 Solar Terms

Twenty-four solar terms refer to beginning of spring, rain, fright, vernal equinox, Qingming, Grain Rain, Changxia, Xiaoman, Mangzhong, Summer Solstice, Slight Summer, Great Summer, beginning of autumn, Early Summer, Millennium, Autumn Equinox, Cold Dew, Early Frost, beginning of winter, Light Snow, Winter Solstice, Slight Cold and Great Cold in turn, in which the odd order is called solar terms and the even order is called solar terms. What is the significance of the 24 solar terms and how are they arranged in the calendar?

The twenty-four solar terms actually divide the apparent motion of the sun into 24 equal parts in a year. According to China Gudu, one day of the week is 365.25 degrees, and each equal part is a little more than 15 degrees. For a long time, the ancients in China thought that the sun was moving at a uniform speed and walked once a day, so each division was equivalent to 15 days or more. According to the actual observation, the ancients obtained the moment when the winter solstice occurred in a certain year, and then accumulated from this moment. In winter solstice, light snow is accumulated for more than 15 days, and heavy snow is accumulated for more than 15 days. By analogy, we can get the solar terms for the whole year.

Because the twenty-four solar terms completely describe the movement of the sun and are closely related to climate change; The change of natural phenology and the time for farmers to sow autumn seeds in spring are directly determined by the climate. Therefore, the 24 solar terms are mostly named after phenological changes and crop growth. For example, "Jing Zhe" refers to the sound of spring thunder, which gives an alarm to small animals that are dormant and hibernating underground, and they will come out to move; "Miscanthus" means that crops with awns begin to mature, and it is time for autumn crops to start sowing. Arranging the twenty-four solar terms is also an important part of China's ancient calendar.

Knot a rope, remember the date, carve wood, and meet each other after a brief encounter.

Living in modern times, we can always know what day it is today. Because there are calendars everywhere on our walls, desks, watches and computers. They are so ordinary in our lives that we ignore them.

But in ancient times, people didn't have calendars to record this day. What should they do? A person has to leave home. How did he know how many days he had been away from home? In order to solve this problem, the ancients came up with a method of "tying the rope to record the day". When a person wants to travel far away, tie a rope around his waist and tie a knot on the rope one day. After arriving at the destination, count the knots on the rope and you will know how many days he has been gone. When I return to China, I will untie a knot in one day. When all the knots are untied, almost everyone will go home. This method was still used by some ethnic minorities in China in the 1940s and 1950s.

If two people make an appointment to meet again in ten days, cut ten notches on a small piece of wood or bamboo, then split it in the middle and take half. Every day, two people cut a gap. When the ten nicks on the bamboo piece are cut, the day will come when they meet again. This is the "woodcut meeting".

Calendar in Oracle Bone Inscriptions

Emperors and nobles in the Yin and Shang Dynasties often asked fortune tellers: What's the weather like recently? How is the agricultural harvest this year? Is the solar eclipse or lunar eclipse that occurs on a certain day in a certain year a good omen or a bad omen? The fortune teller will carve these problems on the tortoise shell with a bronze knife, and then burn the inside of the tortoise shell with a red-hot bronze sign. The scorching bronze sign will split the tortoise shell with different lines, and the fortune teller will answer the questioner according to these lines. These characters engraved on tortoise shells became the oldest ancestor of Chinese characters: Oracle Bone Inscriptions.

On several pieces of Oracle bones unearthed from Yin Ruins in Anyang, Henan Province, sixty tables of branches are neatly carved. These Oracle bones do not have burning marks like other Oracle bones, so they are obviously not used for divination. Later generations speculated that it may have played the role of a calendar in the Yin and Shang Dynasties, which was specially used to record the sun. The method of recording the sun by branches is to use ten days in turn: A, B, C, D, E, Ji, Ke, Xin, Ren, Gui and twelve branches: Zi, Ugly, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu and Hai, and cycle 60 times. If we assume that one day is Jiazi Day, then the next day is Ugly Day, the third day is Bingyin Day, and so on. It is an important creation of the ancient people in China to remember the Japanese method by cadres and branches. As for the Yin calendar, it is generally believed that it records the phase changes of the sun and the moon, as well as the annual movements of the moon and the sun. Twelve months in a normal year, leap year 13 months, and the leap month added at the end of the year is called March. There are big and small months, the big month is 30 days, the small month is 29 days, and even there is a big month between the big month and the small month.

astrology

Let's start with an astrological story and get a general understanding of how astrologers in ancient China used astrology. During the Northern and Southern Dynasties, Ho Choi of the Northern Wei Dynasty was not only an adviser to the emperor, but also a famous astrologer. He often participated in the decision-making of state affairs through astrology. On one occasion, Taishiling reported to the emperor that Mars, the official residence of Papaya Star, somehow lost its trace and may have landed in a certain country, which brought disaster to that country. The emperor was frightened and immediately asked the minister where Mars had gone.

Twenty-eight Nightplates of Han Dynasty Unearthed in Fuyang, Anhui Province

According to the two days when Mars disappeared, namely "Gengwu" and "Xin Wei", Ho Choi judged that, according to an extremely high score, and Orfila were the dividing lines of Qin, so Mars must have gone to the later Qin Dynasty (a small country at the same time as the Northern Wei Dynasty). At that time, no minister in North Korea believed Ho Choi. As a result, 80 days later, Mars really appeared in the split state of Qin and stopped at. That year, after the Qin drought, rumors spread everywhere and people's hearts floated. The next year, the king died and his two sons fought with each other. Within a few years, the country collapsed. This time, astrology is called God. In fact, Ho Choi knows that Mars is anterograde, retrograde and conservative. With a little calculation, he can know where Mars has gone. Moreover, as an adviser to the emperor, he mastered a lot of social and political situations in the late Qin Dynasty, so his judgment on the fate of the country in the late Qin Dynasty was not mysterious.

boundary

During the Spring and Autumn Period and the Warring States Period, many vassal states were enfeoffed. This poses a problem for astrologers: the world is so big and there are so many vassal States, but there is only one sky. If there is some astronomical phenomenon in the sky, which country and region should be warned? The ancient China people's solution was to let the states and countries on the ground carve up the celestial sphere, so that the celestial phenomena that appeared in a certain region one day would correspond to the heads of a certain state and country. This is the theory of dividing line.

Jin Shu? Tianwenzhi records the list of twelve ancient countries, namely Yanzhou, Yuzhou, Youzhou, Yangzhou, Qingzhou, Bingzhou, Xuzhou, Jizhou, Yizhou, Yongzhou, Sanhe and Jingzhou, and includes twelve ancient countries of Zheng, Song, Yan, wuyue, Qi, Wei, Lu, Zhao, Wei, Qin, Zhou and Chu. For twenty-eight lodgings, because twenty-eight is not an integer multiple of twelve, and the scope of twenty-eight lodgings is wide or narrow, astrologers divide some lodgings and let the same lodgings belong to different States and vassal States.

From the Book of Jin? Judging from the division names of the twelve countries recorded in Tian Wenzhi, the division theory as the basis of astrology may have taken shape in the Spring and Autumn Period and the Warring States Period, but as early as in Zhou Li, there was a saying: "Distinguish the land of Kyushu by the stars, and all the surrounding territories are divided into stars to watch the bad luck", which almost involved all the main points of the division theory.

Chronology of old stars

Jupiter is the age star, and period of revolution is 1 1.86 years. According to the ancients, Jupiter will appear in the same sky area in about twelve years. So people divide the equatorial belt into 12 equal parts, which are called,,, building, beam, stone god, quail head, quail fire, quail tail, birthday girl, fire and wood analysis in turn from west to east. This division method is called "twelve times". When some important historical events occur, writing down Jupiter's position in the twelve times will explain the time of the events. For example, when defeating Yin in Mandarin, he said, "The king of Wu cut his sword and lived in quail fire at the age of eighteen." . This chronology is called chronology.

Twelve times in twelve days.

obliquity of the ecliptic

The earth has revolution and rotation, and the great circle formed by its orbit extending outward and intersecting with the celestial sphere is called the ecliptic; The great circle formed by the rotation orbit surface extending outward and intersecting with the celestial sphere is called the equator. The ecliptic plane and the equatorial plane do not overlap, and there is an included angle of about 24 degrees between them, which is called the intersection angle of the ecliptic plane and the equatorial plane. China called it Huang Chi distance in ancient times.

The armillary sphere was the main instrument for measuring the five-star position of the sun, the moon and the sun in ancient China, and the data it measured was the equatorial coordinates of celestial bodies. As we all know, the sun runs on the ecliptic, and other moons and five planets also run near the ecliptic, so when the ancients compiled calendars, they often converted equatorial coordinates into ecliptic coordinates. In order to do this conversion, it is inevitable to use Huang Chijiao's data. People in the Han Dynasty generally believed that the late intersection angle between Huang and Huang was about 1 min. The error measured by Xu Ang in the Tang Dynasty was 37 seconds, which reached a fairly high accuracy.

The Zhousuanjing records a very simple method of measuring the distance between Huang Chi and Chi with eight feet. The shadow length of the table measured at noon from winter solstice is one foot three feet, and the shadow length from summer solstice is one foot five inches. Knowing the geographical latitude of the survey, using the most basic astronomical knowledge and triangular knowledge, we can get the distance of Huangchi.

precession of the equinoxes

Precession is due to the attraction of the sun, moon and planets to the protruding part of the earth's equator, which changes the direction of the earth's rotation axis. Many people played with a small toy called a gyro when they were young. The earth's axis of rotation is constantly changing, just like a big gyro that rotates obliquely. At the same time, the rotating shaft rotates in circles in the sky, but the speed is not as fast as that of the toy gyro. It takes one day for the earth to rotate once, but it takes about 26,000 years for its rotation axis to rotate once in the air. This slow movement is called precession. Precession is manifested in two aspects in astronomical observation: one is the intersection of the ecliptic and the equator: vernal equinox and vernal equinox move westward along the ecliptic; First, the north celestial pole is constantly changing its position in the star background.

Precession genetic map

The vernal equinox moves westward.

In A.D. 330, Yu of the Eastern Jin Dynasty observed the moment when a star passed through the south meridian at dusk, and compared it with ancient records. He found that the vernal equinox in spring and autumn and the solstice in winter and summer had moved westward, so he came to a very important understanding: the time taken for the sun to turn around in a certain position in the star background and then return to its original position is not equal to the time interval from one winter solstice to the next. So he put forward the view that "the sky is the sky, and the age is the age", which is the concept of precession. At the same time, he also gave the data that the winter solstice moved westward along the equator every 50 years, which became the beginning of determining the age difference more and more accurately in ancient China.

On several pieces of Oracle bones unearthed from Yin Ruins in Anyang, Henan Province, sixty tables of branches are neatly carved. These Oracle bones do not have burning marks like other Oracle bones, so they are obviously not used for divination. Later generations speculated that it may have played the role of a calendar in the Yin and Shang Dynasties, which was specially used to record the sun. The method of recording the sun by branches is to use ten days in turn: A, B, C, D, E, Ji, Ke, Xin, Ren, Gui and twelve branches: Zi, Ugly, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu and Hai, and cycle 60 times. If we assume that one day is Jiazi Day, then the next day is Ugly Day, the third day is Bingyin Day, and so on. It is an important creation of the ancient people in China to remember the Japanese method by cadres and branches. As for the Yin calendar, it is generally believed that it records the phase changes of the sun and the moon, as well as the annual movements of the moon and the sun. Twelve months in a normal year, leap year 13 months, and the leap month added at the end of the year is called March. There are big and small months, the big month is 30 days, the small month is 29 days, and even there is a big month between the big month and the small month.

astrology

Let's start with an astrological story and get a general understanding of how astrologers in ancient China used astrology. During the Northern and Southern Dynasties, Ho Choi of the Northern Wei Dynasty was not only an adviser to the emperor, but also a famous astrologer. He often participated in the decision-making of state affairs through astrology. On one occasion, Taishiling reported to the emperor that Mars, the official residence of Papaya Star, somehow lost its trace and may have landed in a certain country, which brought disaster to that country. The emperor was frightened and immediately asked the minister where Mars had gone.

Twenty-eight Nightplates of Han Dynasty Unearthed in Fuyang, Anhui Province

According to the two days when Mars disappeared, namely "Gengwu" and "Xin Wei", Ho Choi judged that, according to an extremely high score, and Orfila were the dividing lines of Qin, so Mars must have gone to the later Qin Dynasty (a small country at the same time as the Northern Wei Dynasty). At that time, no minister in North Korea believed Ho Choi. As a result, 80 days later, Mars really appeared in the split state of Qin and stopped at. That year, after the Qin drought, rumors spread everywhere and people's hearts floated. The next year, the king died and his two sons fought with each other. Within a few years, the country collapsed. This time, astrology is called God. In fact, Ho Choi knows that Mars is anterograde, retrograde and conservative. With a little calculation, he can know where Mars has gone. Moreover, as an adviser to the emperor, he mastered a lot of social and political situations in the late Qin Dynasty, so his judgment on the fate of the country in the late Qin Dynasty was not mysterious.

boundary

During the Spring and Autumn Period and the Warring States Period, many vassal states were enfeoffed. This poses a problem for astrologers: the world is so big and there are so many vassal States, but there is only one sky. If there is some astronomical phenomenon in the sky, which country and region should be warned? The ancient China people's solution was to let the states and countries on the ground carve up the celestial sphere, so that the celestial phenomena that appeared in a certain region one day would correspond to the heads of a certain state and country. This is the theory of dividing line.

Jin Shu? Tianwenzhi records the list of twelve ancient countries, namely Yanzhou, Yuzhou, Youzhou, Yangzhou, Qingzhou, Bingzhou, Xuzhou, Jizhou, Yizhou, Yongzhou, Sanhe and Jingzhou, and includes twelve ancient countries of Zheng, Song, Yan, wuyue, Qi, Wei, Lu, Zhao, Wei, Qin, Zhou and Chu. For twenty-eight lodgings, because twenty-eight is not an integer multiple of twelve, and the scope of twenty-eight lodgings is wide or narrow, astrologers divide some lodgings and let the same lodgings belong to different States and vassal States.

From the Book of Jin? Judging from the division names of the twelve countries recorded in Tian Wenzhi, the division theory as the basis of astrology may have taken shape in the Spring and Autumn Period and the Warring States Period, but as early as in Zhou Li, there was a saying: "Distinguish the land of Kyushu by the stars, and all the surrounding territories are divided into stars to watch the bad luck", which almost involved all the main points of the division theory.

Chronology of old stars

Jupiter is the age star, and period of revolution is 1 1.86 years. According to the ancients, Jupiter will appear in the same sky area in about twelve years. So people divide the equatorial belt into 12 equal parts, which are called,,, building, beam, stone god, quail head, quail fire, quail tail, birthday girl, fire and wood analysis in turn from west to east. This division method is called "twelve times". When some important historical events occur, writing down Jupiter's position in the twelve times will explain the time of the events. For example, when defeating Yin in Mandarin, he said, "The king of Wu cut his sword and lived in quail fire at the age of eighteen." . This chronology is called chronology.

Twelve times in twelve days.

obliquity of the ecliptic

The earth has revolution and rotation, and the great circle formed by its orbit extending outward and intersecting with the celestial sphere is called the ecliptic; The great circle formed by the rotation orbit surface extending outward and intersecting with the celestial sphere is called the equator. The ecliptic plane and the equatorial plane do not overlap, and there is an included angle of about 24 degrees between them, which is called the intersection angle of the ecliptic plane and the equatorial plane. China called it Huang Chi distance in ancient times.

The armillary sphere was the main instrument for measuring the five-star position of the sun, the moon and the sun in ancient China, and the data it measured was the equatorial coordinates of celestial bodies. As we all know, the sun runs on the ecliptic, and other moons and five planets also run near the ecliptic, so when the ancients compiled calendars, they often converted equatorial coordinates into ecliptic coordinates. In order to do this conversion, it is inevitable to use Huang Chijiao's data. People in the Han Dynasty generally believed that the late intersection angle between Huang and Huang was about 1 min. The error measured by Xu Ang in the Tang Dynasty was 37 seconds, which reached a fairly high accuracy.

The Zhousuanjing records a very simple method of measuring the distance between Huang Chi and Chi with eight feet. The shadow length of the table measured at noon from winter solstice is one foot three feet, and the shadow length from summer solstice is one foot five inches. Knowing the geographical latitude of the survey, using the most basic astronomical knowledge and triangular knowledge, we can get the distance of Huangchi.

precession of the equinoxes

Precession is due to the attraction of the sun, moon and planets to the protruding part of the earth's equator, which changes the direction of the earth's rotation axis. Many people played with a small toy called a gyro when they were young. The earth's axis of rotation is constantly changing, just like a big gyro that rotates obliquely. At the same time, the rotating shaft rotates in circles in the sky, but the speed is not as fast as that of the toy gyro. It takes one day for the earth to rotate once, but it takes about 26,000 years for its rotation axis to rotate once in the air. This slow movement is called precession. Precession is manifested in two aspects in astronomical observation: one is the intersection of the ecliptic and the equator: vernal equinox and vernal equinox move westward along the ecliptic; First, the north celestial pole is constantly changing its position in the star background.

Precession genetic map

The vernal equinox moves westward.

In A.D. 330, Yu of the Eastern Jin Dynasty observed the moment when a star crossed the southern meridian at dusk, and compared it with ancient records. He found that the vernal equinox in spring and autumn and the solstice in winter and summer had moved westward, so he came to a very important understanding: the time taken for the sun to turn around in a certain position in the star background and then return to its original position is not equal to the time interval from one winter solstice to the next. So he put forward the view that "the sky is the sky, and the age is the age", which is the concept of precession. At the same time, he also gave the data that the winter solstice moved westward along the equator every 50 years, which became the beginning of determining the age difference more and more accurately in ancient China.