Is "Hope" Day 16 or 17?

July is the sixteenth day of the lunar calendar, and July in ancient times is also a big month. Our current calendar has been circulated for thousands of years, but some festivals that were not found in ancient times have been added, and the calculation of big months and small months is the same.

Looking at the sun:

Wànɡ li

Astronomy refers to the day when the moon is full, usually refers to the fifteenth day of each month in the summer calendar, sometimes the sixteenth or seventeenth day.

Common sense of ancient calendar in China

I. Basic concepts

A. day, month, year, year

The celestial phenomena often observed by the ancients are the appearance of the sun and the profit and loss of the moon, so the cycle of alternating day and night is a "day" and the cycle of phase change of the moon is a "month" (called the early moon in modern times).

The concept of "year" is related to agriculture. Shuowen: "Year, cooked food is also". The maturity cycle of grain is the cold and summer cycle, that is, the time for the earth to orbit the sun once, which is called the solar year. In ancient times, there was a difference between years and years. "Year" refers to the same solar term from one solar term this year to the next, and "Year" refers to the first day of the first month of this year to the first day of the first month of the next year.

B. lunar calendar

The calendar with the moon as the unit is the lunar calendar, and the calendar with the solar year as the unit is the solar calendar. In ancient China, the calendar was not a pure lunar calendar, but a combination of yin and yang. Average one year 12 months, 30 days for six big months and 29 days for six small months. There are big and small moons, because the phase of the moon changes between 29 and 30 days (the exact value is 29.53 days). Every year is 12 months and 354 days, but this figure is not enough for 1 solar year. The actual time for the earth to go around the sun is 365.2422 days, which is more than the sum of the lunar calendar 12 months 1 1 day. So every three years, the difference between the lunar calendar and the actual solar year is 1 month, so every three years, 1 month will be added, which is called leap month. This is to make the average time over the years equal to 1 solar year, which is roughly in line with the natural season.

Jumping is an important event in the ancient calendar. Zuo Wen Zhuan's Six Years in Office: "Leap with time, do things with time, do things well, and have such a good way of dealing with the world." It is not enough to leap once every three years, but twice every five years. Therefore, Shuowen said that "leap again every five years" was a bit excessive, and later stipulated that 19 leap for seven months.

The insertion of leap month was recorded in the Yin and Zhou Dynasties, and leap month was generally placed at the end of the year. At that time, leap had not been customized, and some years even had two leaps a year. But in the spring and autumn period, there was no more. The leap in the early Han Dynasty was placed after September, which was called "the last September". In ancient times, leap was placed in the middle of a year, such as March and June. When you jump without jumping, it is called "missing jump". How to insert it is an important problem in ancient calendars.

C. four seasons

A year is divided into four seasons: spring, summer, autumn and winter, and then divided into Meng Chun, Midspring, Ji Chun, Xia Meng, Midsummer, Late Summer, Qiu Meng, Midautumn, Qiu Ji, Mengdong, Midwinter and Jidong according to the twelve months of the first month, February and March of the summer calendar. Ancient books often use these names as synonyms for months. "Chu ci? Mourning said: "The people are separated from each other, and Fang Zhongchun moves eastward." Midspring here refers to February in the summer calendar.

In the Shang Dynasty and the early Western Zhou Dynasty, a year was only divided into spring and autumn, so the later spring and autumn meant a year. Zhuangzi? Wandering around: I don't know the spring and autumn, which means that my life is less than one year. In addition, the historical materials recorded by historians were also called the Spring and Autumn Period in ancient times, because all the historical materials were written in chronological style. Later, the calendar became more and more detailed, and the two hours in spring and autumn were divided into two hours in winter and summer. Some ancient books list the four seasons in the order of "spring, summer, autumn and winter" instead of "spring, summer, autumn and winter". Like Mozi? The system of "in the sky" is four seasons, spring, summer, autumn and winter, with discipline "and" tube " Juvenile Official Seal: Constant Sacrifice in Spring, Summer, Autumn and Winter, Book of Rites? Confucius lived in seclusion: "There are four seasons in the sky, spring, summer, autumn and winter" and so on.

Second, solar terms

A. names of solar terms

According to the laws of seasonal change and climate change, the ancients divided 365 days and 1/4 days of a solar year into 24 solar terms, such as beginning of spring, rain and fright. These solar terms are divided equally first, and each solar term averages 15.22 days. According to the speed of the sun's movement, some rules are as follows

14 days (for example, from winter to around), and some regulations are 16 days or more (from summer to around). The names and order of the 24 solar terms are as follows:

The first month: It rains in beginning of spring.

February: vernal equinox

March: Qingming Grain Rain

April: Little Man, Long Summer

May: summer solstice of awn seed

June: light summer and heavy summer

July: Autumn begins in summer.

August: Autumn Equinox of the White Dew

September: the first frost of cold dew

October: light snow in early winter

1 1 month: winter solstice with snow.

1February: slight cold and severe cold

This set of solar terms first appeared in Huainanzi? Astronomical training. Jing Ke was called "Qi Zhe" in ancient times, but Jing Di's name was taboo in Han Dynasty. The collocation of 24 solar terms and months is not absolutely fixed. Because the solar term follows the solar year, it has nothing to do with the new moon. The above is the general situation.

The ancients originally divided the twenty-four solar terms into solar terms and neutral gas. For example, beginning of spring is in the first month, the rain is in the first month, the fright is in February, the vernal equinox is in the middle of February, and so on.

The subdivision of solar terms has a certain relationship with leap. Because it takes about 30.5 days to add 1 solar terms and 1 neutral gas, which is longer than a new moon, the solar terms and neutral gas in each month will be delayed by 1 to 2 days compared with the previous month, and only the solar terms will be delayed to a certain month, and then this month will be a leap. So the ancients said, "leap month is not neutral." The solar calendar has solar terms and a neutral atmosphere every month. The 6th and 2 1 in the first half of the year are festivals, and the 8th and 23rd in the second half of the year are festivals.

B. Establishment of solar terms

The establishment of solar terms is related to astronomy. The ancients divided the sky around the ecliptic into twelve o'clock, such as astrology and mystery. When the sun runs for a certain time, it will pay a certain solar term. In fact, the 24 solar terms are 24 different positions on the earth's orbit around the sun.

Hanshu? Calendar chronicles mentioned the relationship between solar terms and solar terms. For example, when the sun runs at the beginning of astrology, it will turn to winter solstice, when it runs at the beginning of Gong Xuan, it will turn to slight cold, and when it runs in the center of Gong Xuan, it will turn to cold. The comparison of solar terms and solar terms mentioned in the calendar chronicle is as follows:

1. astrology: snowy winter solstice

2. Xuan Biao: slight cold and severe cold

3. Hey: beginning of spring is stunned.

4. Loulou: The rain at the vernal equinox

5. Girder: Qingming in Grain Rain

6. Stone God: Long Summer and Small Man

7. Quail head: summer solstice of mango

8. Quail fire: light summer heat and great summer heat

9. Quail tail: beginning of autumn is in summer.

10. The birthday girl: the Millennium Equinox.

1 1. Fire: first frost and cold dew.

12. Analysis Wood: Xiaoxue, beginning of winter

When the sun moves to the beginning of a star, it is the previous solar term, and if it moves to the center, it is the latter solar term.

This comparison table is mentioned in Hanshu, which is different from before rain and after Qingming in Grain Rain. The astronomical phenomena more than 2000 years ago are different from those in modern times. It is mentioned in Fahuazhi that when the solar term is over, it refers to the star and degree where the sun is, such as the winter solstice at the beginning of morning glory, near the beta star of Capricorn today, and the modern winter solstice in Sagittarius.

C. evolution of solar terms

The 24 solar terms are gradually improving. The ancients mastered the four most important solar terms, the vernal equinox and the summer and winter solstice. "History? Yao Dian is called the vernal equinox in Japan and the autumnal equinox in the middle of the night. Because these two days are equal in length, Lu Chunqiu is called the equinox. Yao Dian called summer a perpetual day and winter a short day because summer has the longest day and winter has the shortest day. Lu Chunqiu called it long day and short day respectively. " "Zuo Zhuan Xi Gong Five Years" said: "Every minute must be opened and closed. "Here, the vernal equinox refers to the spring and autumn equinox, Xia Dong refers to the summer solstice, long summer refers to beginning of spring, and beginning of winter refers to beginning of autumn. Beginning of spring, Chang Xia, beginning of autumn and beginning of winter are clearly recorded in Lu's Spring and Autumn Annals. In Huai Nan Zi, there are 24 solar terms with exactly the same modern names.