On the current lunar calendar calculation in China

Questions and answers about calendar knowledge (1);

What is the basic calendar attribute of 1)?

Answer: lunar calendar, solar calendar, yin and yang calendar;

2) Is the lunar calendar a "lunar calendar"?

A: Not exactly. The lunar calendar is a yin-yang calendar.

3) Is the solar calendar a Gregorian calendar?

Answer: Incorrect. The Gregorian calendar is only a member of the Gregorian calendar, and it cannot be the whole Gregorian calendar.

4) Is the lunar calendar "superstitious"?

A: The lunar calendar is a science, but it is not a superstition.

5) When was the Gregorian calendar used?

A: 1582 was promulgated by Pope Gregory 13, and 19 12 was used in China.

6) What is the current version of the lunar calendar?

A: It was the "Li Shixian" law in the late Ming and early Qing Dynasties, which was officially used in 1645 Lunar Year of the Rooster (this year is the 360th anniversary).

7) Is the current lunar calendar calculated by the calendar of the Qing Dynasty?

A: No, the current lunar calendar is calculated and discharged by the Purple Mountain Observatory of the Chinese Academy of Sciences with the most accurate lunar data. They use modern and advanced orbit calculation method, which is no longer the algorithm of Qing dynasty;

8) Where is the most accurate moon data today?

A: At present, the data of the Jet Propulsion Laboratory under NASA is the most accurate, but the data of the Purple Mountain Observatory in China is almost the same as it (these are also necessary data for manned space flight);

9) Is it true that some people call the lunar calendar "lunar calendar"?

Answer: I don't agree to call the lunar calendar "leap lunar calendar". Personally, it is not accurate. The hijri calendar is the lunar calendar (with leap days), and the lunar calendar is the lunar calendar. The number of months required by the lunar calendar can only be 12 or 13, not other numbers, so it is also inaccurate to call the lunar calendar "leap lunar calendar". Its calendar year is only the accumulation of integer multiples of months, so there can be several leap months in a year (this happened before the Roman solar calendar was changed), and the year of the yin-yang calendar is bounded by the "year" in a clear astronomical sense, that is, the tropic year, so the number of months in its calendar year can only be 12 or 13, and cannot be other numbers;

10)

1 1) Some people call the current lunar calendar "fake lunar calendar", right?

A: Some people call the current lunar calendar a "fake lunar calendar" and say that they want to give farmers a "real lunar calendar". Personally, I can't agree with them.

Because the lunar calendar is a special combination of yin and yang (it is a collection of ordinary yin and yang calendars and special solar calendars), especially because the ordinary yin and yang calendars only have leap months and fixed leap weeks (which belong to the flat atmosphere), and our lunar calendar contains twenty-four solar terms of solar calendar nature, which is a special solar calendar (especially the height of the sun is directly used as the standard for calendar formulation), and seventy climaxes (climate calendars) derived from solar terms become one. The China lunar calendar also includes the dry calendar (solar calendar), which is what people call the true lunar calendar; One of the reasons why they call the lunar calendar a "fake lunar calendar" is that the lunar calendar contains a lunar calendar (that is, the lunar calendar is not a solar calendar). According to the traditional view, the lunar calendar has nothing to do with the climate, but modern science has found that the moon phase also affects the climate, so the moon phase must be considered when making accurate weather forecast and geological disaster forecast. At present, the research on this issue is still in the primary stage; Needless to say, all kinds of proverbs accumulated by working people in our country are based on the lunar calendar (solar terms and calendar days). In addition, the lunar month also plays an irreplaceable role in rural life; Therefore, I think that the current lunar calendar already includes solar terms and solar terms calendar, and it is not unreasonable to call it the lunar calendar.

12) the current lunar leap (leap chapter) "the seventh leap in the nineteenth year"?

A: This is incorrect, and this view must be corrected. Because although most of the current lunar calendar is consistent with the "19-7 leap" method, because the 7 leap method of 19 is a flat gas method, there is still a big error with the tropic year, so the current lunar calendar has been used for a long time;

The correct statement is that the current lunar calendar is a method of "setting a leap in the middle of the atmosphere", or more accurately, "setting a winter solstice" (the month of setting a winter solstice is 1 1 month), so the average length of the lunar calendar is the latest tropical year (this number is also changing), which is about 365.438+09 days. The advantage of using this leap method is that it can always correspond to the tropic of cancer and will not be produced.

13) Is the lunar calendar a special lunar calendar?

A: Yes. This is because there is no obvious combination between the ordinary lunar calendar and the solar calendar, and the lunar calendar is an organic combination of the twenty-four solar terms of the ordinary lunar calendar (the Gregorian calendar year of the lunar calendar) and the special solar calendar (calculated according to the degree of the ecliptic of the sun, designed for the lunar calendar and completely part of the lunar calendar), thus forming an organic whole special lunar calendar (actually a comprehensive calendar);

14) Some people call the lunar calendar a mixed calendar, don't they?

A: This is correct, but the lunar calendar is not a simple mixed calendar. The generalized Gregorian calendar (including the lunar calendar, that is, the narrow solar calendar and the solar calendar, that is, the zodiac calendar) is a simple mixed calendar (they are self-contained and unrelated), and the lunar calendar is a special mixed calendar (that is, the organic combination and unity of the ordinary lunar calendar and the special solar calendar);

15) what should I pay attention to when studying the lunar calendar?

Answer: We should treat all parts of the lunar calendar correctly and as a whole, including the 24 solar terms (the positioning of the solar orbit, the solar calendar in the lunar calendar), the calendar month (the moon and the sun are in different positions, which have the functions of the moon phase and the lunar calendar) and the dry-branch calendar (not the Gregorian year and the dry-branch calendar, but the solar term month starting from the solar term in beginning of spring, which belongs to the Chinese zodiac). Calendar year (Yin-Yang calendar, with the characteristics of Yang year and the specific lunar month, so it is Yin-Yang calendar. ) and its relationship in the lunar calendar, as well as the orbit calculation of various celestial bodies;

16) What is a leap week in the Gregorian calendar?

Answer: The leap day method of 97 in 400 years is specifically: add it to the year in which the AD number is divisible by 4 (except century year), and the century year is divisible by 400;

17) Is a calendar the same as a wall calendar?

A: Calendar and calendar calculation are not the same thing. Calendar is the law and soul of calendar making. Calendar is the calculation method of making calendar and the realization of calendar; They are collectively called almanac; The calendar of China lunar calendar comes from the constitutional calendar, but its current calendar calculation is the most advanced data, formula and theory.

18) What are the ancient calendars in China?

A: Some things can be tested, including those that have been promulgated and those that have not:

According to Wang's Textual Research of Past Dynasties, Zhu Wenxin's Chronology and Mr. China's Calendar History, there were 1 15 calendars in ancient China, and their names can be verified.

1, Huangdi calendar

2. Zhuan Xu calendar

3. Summer calendar

4. lunar calendar

5. Weekly calendar

6. Lu Li

7, calendar art Jiazi calendar

8. Early calendar

9. Three calendars

10, quarterly calendar

1 1, Qiyao Art

12, dry calendar

13, Huang Chu calendar

14, Taihe calendar

15, Jingchu calendar

16, Taishili

17, Liu Zhili

18, dry calendar

19, calendar

20. Yonghe calendar

2 1, three-year Jiazi calendar

Xuan Shi calendar

23. Permanent calendar

24. Three Li Xuanyuan.

25. The past seven obsidian calendars

26.yuan Jiali

Li Jianyuan.

28. Daming Calendar

29. Jingming calendar

30, turtle calendar

3 1, calendar

32. Milky Way Calendar

33. Datong calendar

34. Jiugong Line Answer Calendar

35, seven obsidian calendar

36. Tianbao Calendar

37. Northern week calendar

38. Spiritual calendar

39.Tianhe Calendar

40. Liu Li

4 1, Jiayin Yuanli

42. Meng Libin

43. elephant calendar

44. Open the Imperial Calendar

45, seven obsidian new technique

46. Zhang Zhou Li Xuan

47. The emperor's calendar

48. The Great Calendar

49. Pentaphone Calendar

50. Fu Tianli

5 1, Linde calendar

52, longitude and latitude calendar

53, light house calendar

54. Dragon Calendar

55. Nine calendars

56. Goose calendar

57, chitose calendar

58, seven obsidian calendar

59. Calendar to Germany

60. Five calendars

6 1, positive yuan calendar

62. Observe the calendar

63. Ming calendar

64. Double calendar

65. perpetual calendar

66. Yongchang Calendar

67. Like a calendar.

68. Yuan Calendar

69. Zhongzheng calendar

70.li

7 1, Ming Yuan calendar

72.qin

73. It should be a calendar

74, dry yuan calendar

75. Go to the calendar

76. Liao Daming calendar

77, instrument calendar

78. Dry calendar

79. Worship the calendar

80. Tomorrow's calendar

8 1, Fengyuan calendar

82. Twelve calendars

83. Look at the calendar

84.calendar

85, era calendar

86. Daming Calendar

87. Daming Calendar

Harmonization of calendars

89, trunk highway calendar

90. Cherish spring calendar

Li Zhiwei 9 1

92, B not yuan calendar

93. Five-star reunion calendar

94. Huiyuan Calendar

95. Unified calendar

96. Open the Jubilee Calendar

97, the western expedition 55 yuan calendar

98. Chun Youli

99. Calendar of meetings

100, 10,000 yuan calendar

10 1, full-time calendar

102, this calendar

103, time calendar

104, Baojian calendar

105, hijri

106, big calendar

107, Longevity Calendar

108, Huang Zhongli

109, Gregorian calendar

1 10, new calendar

1 1 1, Xiaoan calendar

Shunzhi calendar 1 12

1 13, constitution calendar

1 14, Guimao Garden

1 15, calendar

19) Is it really a symbol of imperial power?

A: Calendars are not feudal, but in feudal society, feudal owners controlled the formulation of calendars, but now the feudal system has been abolished, so it is no longer a symbol of imperial power.

Now the people are the masters of their own affairs, and they have the right to use or modify their own traditional calendar-the lunar calendar.

20) When was Zheng He's first voyage to the Western Ocean?

Answer: 1405 lunar calendar (which should be the calendar of time service) June 15 (Gregorian calendar July11);

2 1) What is the astronomical significance of the current lunar leap month?

A: Because the current solar terms in the lunar calendar are fixed and the lunar calendar is neutral, the lunar leap month also has its astronomical significance. The number of leap months indirectly reflects an unobvious astronomical quantity, that is, the near precession and near date of the earth;

Most lunar leap months move every 19 years, which fully reflects the eastward movement of the perihelion of the earth and the westward movement of vernal equinox. There are many leap months in the lunar calendar, and there is no leap month in December, which means that the perihelion is in November or December of the lunar calendar and the distant day is in May or June of the lunar calendar.

22) Is it possible for individuals to calculate the lunar calendar at this stage?

A: It is possible. Because with the popularization of astronomy and the improvement of people's scientific and cultural level, the calculation of the lunar calendar is no longer very mysterious. Now there are astronomy enthusiasts who use astronomy to calculate the electronic lunar calendar with high precision and excellent performance.

23) What system is commonly used for astronomical distance calculation?

A: The angle system, that is, astronomical azimuth and distance, is often expressed by angles.

24) What are the "three differences" involved in astronomical calculation?

Answer: Haze (caused by uneven atmospheric refraction), parallax (caused by the change of observer's position) and aberration (caused by the change of observer's moving speed).

25) Some people say that the 24 solar terms are subordinate in the lunar calendar, but are they really subordinate in the lunar calendar?

A: This statement is inappropriate and inaccurate. The 24 solar terms are really the theme of the lunar calendar, which is very important.

First of all, when calculating the lunar calendar, "winter solstice" ranks first. Determining the winter solstice, that is, determining the age of the lunar calendar (whether it is 12 months or 13 months), is also very important in today's lunar calendar calculation (the tropic year is defined by its starting point).

In addition, 12 is a symbol of the lunar calendar and an important basis for the lunar calendar.

12 "Sili" in solar terms is the official starting point of the traditional four seasons in China.

Marking solar terms in the lunar calendar itself embodies the main functions of solar terms and is a sign that the lunar calendar is different from other foreign lunar calendars.

The solar term 12 is the starting point of our traditional calendar (China's zodiac calendar is a part of the lunar calendar, similar to the western zodiac).

In addition, the solar terms of the lunar calendar are "true solar terms" directly calculated from the longitude of the Yellow River, with high accuracy.

26) Why are the lunar calendar and calendar calculations still unknown to people?

A: The lunar calendar is "mysterious" for the following reasons:

1, this is because the lunar calendar and calendar are very complicated and highly accurate astronomical work, which is difficult for ordinary people to calculate and master. But with the popularization of astronomical calendar and mathematics and the application of computers, this is not the main problem;

2) Lunar calendar has the function of predicting astronomical phenomena, and its calculation requires very accurate calculation and observation of astronomical constants and planetary orbits, which requires professional observatories to realize and publish astronomical constants;

Because the lunar calendar was monopolized by the ruling class in feudal society, it is very mysterious. Now that the feudal system has been abolished, the lunar calendar has returned to the masses.

27) What celestial coordinates are commonly used in astronomical calculation?

Answer: horizon coordinate system, time angle coordinate system, equatorial coordinate system and ecliptic coordinate system.

28) What are the astronomical conditions of solar eclipse and lunar eclipse?

A: The ecliptic intersects the white road, and the sun and the moon intersect at the intersection.

29) What are "solar year" and "earth year"?

A: The solar year refers to taking the coordinates of the celestial sphere extended by the earth as the benchmark, and taking the sun on the celestial sphere (which may be a specific position such as the vernal equinox or the same position) as a week.

The year of the earth is called the "solar year" by a more objective embodiment.

30) What are the ecliptic, the white road and the equator?

A: The ecliptic is the orbit of the sun on the celestial sphere;

The white road is the orbit of the moon on the celestial sphere;

The equator is a closed curve (ellipse or circle) that cuts the earth or celestial sphere at 90 degrees to both sides with the axis of rotation and the center of the earth as the center;

3 1) What are precession and nutation?

A: Because the direction of the earth's rotation axis rotates very slowly around the ecliptic, the vernal equinox (the intersection of Huang Chisheng) moves westward relative to the same point of the ecliptic, forming precession; In the process of the earth's rotation axis rotating very slowly around the ecliptic, the uneven distribution of matter on the earth and the gravity of planets such as the moon cause slight jitter, which is called nutation;

32) What basic mathematical knowledge is needed to calculate the lunar calendar?

Answer: Calculus, series, plane geometry, solid geometry, analytic geometry, trigonometry (including ball science) and so on.

33) What astronomical points are needed for lunar calendar calculation?

Answer: Since the current lunar calendar is a fixed calendar, the calculation of the lunar calendar requires the time of the following astronomical points and the longitude of the Yellow River:

Perigee of the moon, apogee of the moon, rendezvous of the sun and the moon, perihelion of the earth, apogee of the earth, 24 solar terms, first quarter moon, full moon and last quarter moon; In addition, there are moments when the earth revolves to a certain point;

34) What are the three elements of the lunar calendar?

Answer: the sun (solar day), new moon (lunar component in the lunar calendar), qi (solar component in the lunar calendar);

35) What's the difference between a fixed calendar and a flat calendar?

A: The calendar is calculated according to various average motion periods of celestial bodies. For the lunar calendar, Ping (flat winding, flat looking, flat lower chord), Ping for the sun, Ping for the lunar calendar.

The cycles used in the calendar usually include tropic year, new moon, recent year, recent month, sidereal year, sidereal month, vernal equinox and so on.

The flat calendar does not involve the specific orbit calculation of celestial bodies, so it is simpler than the fixed calendar.

The fixed calendar is calculated from various special points of celestial bodies, which is a fixed new moon for the lunar calendar (one string is fixed and two strings are fixed); For the sun, it has always been calm; For yin and yang, it has always been said that the new moon is fixed and the qi is fixed (yin and yang calendars only use the new moon, and semi-fixed calendars are one of them);

Regarding the special astronomical points needed to determine the calendar, I asked, "What astronomical points are needed for the calculation of the lunar calendar?" Introduced in;

The determination of calendar involves the calculation of the specific orbit of celestial bodies, which is more complicated than the flat calendar, but it has a strong function of predicting the sky.

Gregorian calendar is flat lunar calendar, Gregorian calendar (Gregorian calendar) is flat solar calendar, and the ancient six calendars (Huangdi calendar, Zhuan Xu calendar, Xia calendar, lunar calendar, Zhou calendar and Lu calendar) in China lunar calendar (generalized lunar calendar) are flat solar calendar;

The current lunar calendar in China is a fixed lunar calendar (in which the dry calendar is a fixed solar calendar);

36) What is a standard calendar?

A: A standardized calendar clearly specifies the number of days in each month and coordinates the corresponding astronomical cycle with a fixed leap week. This calendar is highly mathematical and has little to do with astronomical quantity, so it is transparent, easy to remember and calculate, and belongs to a flat calendar;

Gregorian calendar and Gregorian calendar are standard calendars;

37) At present, some people still refer to the Gregorian calendar as the "new calendar", but is it appropriate to refer to the traditional calendar of China as the "old calendar"?

A: Not appropriate. Calling the Gregorian calendar "new calendar" is the name of the early years of the Republic of China compared with calling the current lunar calendar "old calendar", but it is understandable in the Ming Dynasty (because the Gregorian calendar is a new calendar for China people, but it is actually not new and even older than the current lunar calendar in China), but it is appropriate to call it this way after understanding the history of the Gregorian calendar;

The current Gregorian calendar (Gregorian calendar) was implemented in 1582, while the current China lunar calendar (time constitutional calendar, also called new calendar) was implemented in 1644, which is later than Gregorian calendar; Therefore, the "old calendar" (called the current lunar calendar in the early years of the Republic of China) is not old, and the "new calendar" (called the current Gregorian calendar in the early years of the Republic of China) is not new. China is used because of its versatility;

At the same time, it is also inappropriate to call the lunar calendar "lunar calendar", which is also the name of the early years of the Republic of China. This name is only relative to calling the Gregorian calendar "Gregorian calendar".

38) What are cumulative chronology and cyclic chronology?

A: The cumulative chronology method is to set an initial year (epoch) first, and then the chronology method with uninterrupted and non-repetitive numbers;

Cyclic chronology is a cyclic chronology with a set of ordinal numbers (limited and fixed in number);

The current chronological method is cumulative chronological method, and the Gregorian calendar year is the first year of AD. The lunar calendar in China has always adopted the method of trunk and branch chronology in cyclic chronology;

These two dating methods have their own characteristics. In addition, the chronology of the Yellow Emperor was given in the early years of the Republic of China (starting from the Spring Festival). Now it is mainly implemented abroad. After the Spring Festival in 2005, it was the year 4703 of the lunar calendar, the third year of the 48th lunar calendar in China.

39) What are the parts of the current lunar calendar in China?

A: The most fundamental part consists of two parts, namely, the lunar calendar and the solar terms, and other parts are derived from these two parts. It includes the following parts:

First, the calendar part of the lunar calendar (including the trunk and branch of the calendar, which is different from the trunk and branch calendar mentioned later); Second, solar terms and seventy-two periods; Third, miscellaneous solar terms; Fourth, the official calendar [The zodiac calendar in the China lunar calendar (December, that is, the zodiac in China) is a part of the lunar calendar, which was developed according to the idea of the Twelve Qi Calendars written by Shen Kuo in the Song Dynasty. ];

Note: The lunar month corresponds to the solar longitude of twelve qi.

The algorithm of the calendar in the lunar calendar is as follows: the starting point of the annual calendar is the time of beginning of spring in the lunar calendar (note that it is not the zero point of beginning of spring day); The starting point of each month is twelve knots (note that it is not necessarily 0: 00 on Boxing Day); Adopt a long-term uninterrupted calendar method (China has used it for thousands of years); The time is fixed at 12, and the time comes from the same day.

Because the solar terms of the lunar calendar use fixed qi, it corresponds to meridian 0 degrees from the vernal equinox, and from then on each solar term is 15 degrees, and the 24 solar terms of the ecliptic total 360 degrees.

40) What is the waiting time for the Lunar New Year?

A: After 24 solar terms, China people refined the solar terms into climate, which is a smaller solar calendar unit in the China lunar calendar.

Starting from beginning of spring at the earliest, the waiting period is 5 days, and there are 73 days in a year (the last waiting period is 6 days or 7 days), which is simple flat weather (similar to flat weather);

Later, when it was combined with the twenty-four solar terms, the 1 climate was removed, which became the 72 climate from beginning of spring, that is, "one (one) trachea and three climates", which became the refinement unit of solar terms, making the flat gas correspond to the flat gas; Taking the horizontal climate corresponding to the steady gas as the semi-steady climate;

Liu Zhuo, an ancient calendarist, put forward the theory of "timing", which means that every 5 degrees on the ecliptic is 1, not necessarily 5 days.

The current lunar calendar in China adopts a fixed atmosphere and a fixed climate;

Although all the above periods are not necessarily five days, the "waiting" as a unit of time is five days.

Personally, I think there is also a kind of "standard weather", just like the current "ten days". There are three weather periods in one breath, the first two wait for five days, then wait for 1 until 1 before the next solar term.

Climate is a necessary supplement to solar terms. Together with the twenty-four solar terms, it forms the solar calendar in the China lunar calendar. It is a unique solar calendar system in China lunar calendar, an important thought of China lunar calendar and our spiritual wealth.

4 1) did ancient Rome also use the yin-yang calendar?

A: They have, but the lunar calendar they use is very simple (it can't correspond to the moon well, and there is no solar calendar system similar to the 24 solar terms in China.

42) Why is the time unit of "one inch of time and one inch of gold" "inch"?

A: This sentence means that time is precious; However, time is measured in inches, because ancient people used sundials to measure time or poles to measure the length of shadows. Of course, the unit of time is inches.

43) What is the Zodiac?

A: Due to the influence of precession and nutation, Ophiuchus is short-listed instead of twelve constellations that depend on the sun, thus changing from "Twelve Zodiac Constellations" to "Thirteen Zodiac Constellations". The new Ophiuchus is in the middle of the time when the sun passes through Scorpio twice. For details, please refer to the relevant materials of Chinese Academy of Sciences.

In fact, the constellation is based on the time when the sun runs to the same point (that is, the sidereal year) as the corresponding point, with the sidereal year as the cycle, which is about 365 days, 6 hours and 9 seconds; The difference between it and the tropic year is "precession";

44) What is the definition of "sea" in navigation?

Answer: Because longitude is often used in navigation, it is stipulated that every 1 angle on the earth's equator is divided into1nautical mile, which is 360 * 60th of the length of the earth's equator (about 40076km) and about 1.852km. ..

45) Is the statement that "the earth goes around the sun once a year" accurate?

A: Strictly speaking, this statement is not accurate, and it is an approximate vague statement, because the average Gregorian calendar year in our commonly used calendar is close to the tropic year, and "the earth revolves around the sun once" actually refers to the sidereal year (6: 06: 09 on 365), which is precession from the tropic year (5: 48: 56 on 365).

46) At this stage, what is the goal of Gregorian calendar reform?

A: The objectives of the current Gregorian calendar reform are as follows:

The first is the reform of leap week, which changes from 97 leap days in 400 years to more accurate 128 3 1 leap or other schemes;

Second, the reform of fixed number of days per month should generally adopt 30 days and 3 1 day or other schemes;

Third, the first year of reform is set in beginning of spring, that is, the average date of winter solstice; Note that I also have a plan to set the average date of the vernal equinox.

Fourth, the change of the times, the current era (the first year of AD) is in the middle of the development of human history, which brings inconvenience to upward calculation and has a strong religious color. It is suggested to change it to the early stage of human civilization;

Fifth, the reform of the week, which is also the focus of debate, many schemes cancel the continuity of the week, but adopt "empty days" or "quasi-weeks" or change to a five-day week system (leap years should also be quasi-sundays);

47) What is the goal of perfecting the current lunar calendar?

Answer: The lunar calendar is not the official calendar of China, but a folk calendar. The main purpose of keeping it is to supplement the official calendar (Gregorian calendar) and protect the folk culture of our nation, so we should emphasize its advantages and make it correspond to the astronomical phenomena more one by one.

The objectives of reform and improvement are as follows:

One is the leap method, which uses the uniform leap method in the calendar;

Secondly, the calendar method applies the most advanced theories and algorithms, such as the relativistic algorithm;

Third, the cumulative calendar year of the lunar calendar, the Gregorian calendar year (the era of the Yellow Emperor) and the comprehensive calendar year of the trunk and branch zodiac were officially launched. For example, this year, after the Spring Festival of the Gregorian calendar in 2005, it will be the Year of the Rooster in 4703 and the Year of the Dog in 4704 in 2006.

Fourth, some of the 72 waiting names (difficult to understand, unfamiliar or inappropriate) can be replaced by new waiting names (concise and clear);

Fifth, increase the morning and evening shadows, sunrise and sunset tables and solar eclipse forecasts marked by latitude and longitude;

48) Why do three big months sometimes appear in the lunar calendar?

A: Because the current lunar calendar adopts a fixed new moon, that is, the first day is the day when the sun meets the moon (this is a specific astronomical phenomenon, and there is no moon on this day), the number of days between the two first days is determined by the astronomical phenomena and is not fixed, so this is likely to happen.

The lunar month appears in a very small number, with four big months in a row.

Although the number of days in the lunar calendar is determined by the new moon, which brings some inconvenience to people's memory, it is more in line with the astronomical phenomena and more advanced in astronomy.

49) How to determine the size of the second day of the second lunar month?

A: In most parts of China, after sunset (evening) on the second day of the second day, whether there is a thin crescent moon in the western sky can be observed. If there is a crescent moon, it means that the first day is late, so this month is longer, but the big month is 30 days;

There is no crescent moon, which means that the first day of the lunar calendar happened earlier, and this is shorter, which is abortion, which is 29;

This method is accurate in most cases, except for a few cases;

In the lunar month, the moon is generally sixteen laps (looking at the sun), and in the abortion month it is generally fifteen laps (looking at the sun);

50) Why is Wang Shuo's moon longer than the star moon by more than two days?

Answer: 1 Shuowangyue (moon phase cycle) is about 29.53059 days, while the sidereal moon (the time for the moon to revolve around the earth once) is about 27.32 166 days. The difference between the two is more than two days. This is because while the moon revolves around the earth, the earth also takes it around the sun at a certain angle, so it can be seen that the moon is one.