Who can tell me the difference between lunar calendar and solar calendar, and what are their advantages and disadvantages?

Lunar calendar, solar calendar, yin and yang calendar

Human life and production are always inseparable from time and space. How to remember, express clearly to others or even accurately record an event or phenomenon requires a fixed method, which is the problem of Gregorian year, Gregorian month, Gregorian day and Gregorian calendar.

It is easy to observe a day consisting of sunrise, sunset and day-night cycle. The longer the moon, the longer the month and the longer the year. After long-term observation, it is found that the full period and short period of the moon (the first month of the lunar calendar) are about 30 or 29 days, and the seasonal period (the tropic year) is about 365 or 366 days. If we don't follow these standards, but take the orientation of the sun and the moon in the stellar background of the celestial sphere as the standard, then in astronomy, there are also sidereal months (shorter than the moon) and sidereal years (slightly older than the regression). Others include the near-point month and the intersection month, so I won't talk about it here.

Year, month and day are endless cycles. Originally, there was no beginning or end, but for convenience, people always designated a beginning. Different nationalities, different regions and different times have different regulations, so the problem of mutual conversion between the beginning of the year and the beginning of the month arises.

There are several ways to calculate the beginning of a day, such as dawn, pingdan, sunset and midnight.

There are several ways to calculate the beginning of a month, such as starting from the full moon and starting from the appearance of the new moon.

At the beginning of a year, there are many calculation methods, such as winter solstice, vernal equinox, and other signs.

The most troublesome problem is that a new moon is not exactly thirty days, but a little over twenty-nine and a half days. But in real life, we can't divide a day into two halves, so that the upper part belongs to last month and the lower part of the same day belongs to the next month. That's too inconvenient. If 365 days of a year are defined as 12 months ***354 days, there is still 1 1 day left. There is no common multiple between 29.5309 days of the moon and 365.2422 days of the Tropic of Cancer, so a cycle cannot be formed. What should we do?

It is precisely because of the different ways to deal with these problems that various calendars have appeared in the world. To sum up, there are only three kinds: lunar calendar, solar calendar and combined calendar of yin and yang. The first two only care about one end, and the third is to take care of both ends.

Let's talk about the lunar calendar first. Simply put, it is based on the cycle of the moon. The so-called "simplicity" means only caring about the moon, regardless of seasonal changes such as climate change caused by the relationship between the sun and the earth. The moon is also called "lunar calendar", so this calendar is called "lunar calendar" for short. When the moon and the sun are just on both sides of the earth, the soft moonlight shines on the sleeping earth all night. The most round moment of the moon is called "full moon", also called "looking". Because the moon is always in motion; So strictly speaking, the real "lookout" is only a very short moment. For an instant, ordinary people can't observe such subtle changes. Usually, the whole day including the real "lookout" is called "lookout day", or simply "lookout", which is one of the most easily observed and remarkable astronomical phenomena. On the contrary, when the moon is between the sun and the earth, people can't see any images of the moon at all. This day is called "New Moon". Astronomy refers to the moment when the longitude of the ecliptic of the moon coincides with the longitude of the ecliptic of the sun. Astronomers call the period of moon phase change, that is, the length of time from new moon to new moon or from looking to looking, "Shuowangyue", and the Tibetan calendar is called tshes-zla, which can also be translated as "lunar month". Many years' observation shows that the length of Wang Shuo's moon is not fixed, and its average length is 29 days 12 hours and 44 minutes, that is, 29.5306 days, which is very important data for making calendars and must be firmly remembered. It can be roughly recorded as 29 and a half days.

The most typical lunar calendar is the "monthly calendar" (different from the "palace calendar" used in agriculture) in Islamic calendar, which was called "Hui Hui calendar" in ancient China. It always takes 12 lunar months as a year, with an average of 29.5 days per month, and 12 ***354 days. At the end of leap year, 355 days plus 10 days, and there is no leap month.

In addition, we know that human life and production, especially in temperate regions of the earth, are closely related to the climate change of warm spring, hot summer, cool autumn and cold winter. This year consists of four seasons: spring, summer, autumn and winter. It is called "tropic year", that is, the cycle of the sun from the highest to the lowest, and then from the lowest to the highest. Its strict definition in astronomy is: "the time interval between two consecutive passes through vernal equinox on weekdays." According to the results of long-term astronomical observation, it is known that the length of the tropic of cancer is 365.2422 days a year, that is, 365 days, 5 hours, 48 minutes and 46 seconds, which is another very important data when making calendars. It must be firmly remembered that it can be roughly recorded as 365 days 1/4 days. The data obtained by ancient calendar mathematicians did not reach such accuracy at once, but gradually approached the accuracy with the development of calendar.

It can be seen that the difference between the tropic year and the lunar year (that is, the lunar year in Islam) is 1 1 day, and after 7 years, it will accumulate to about 180 days, which means it will be reversed in winter and summer. There is no leap month in the pure lunar calendar, but there are leap months in both Tibetan and lunar calendars, although the average year is 354 or 355 days, and the year with leap months is 384 days. Therefore, it cannot be said that the lunar calendar is a lunar calendar, and the Tibetan calendar is not a lunar calendar, but a yin-yang calendar.

2. Summer calendar, lunar calendar and old calendar

Let's start with the origin of the name "Li Xia". As early as 2400 or 500 years ago, Han people began to calculate the twelve earthly branches (Zi, Ugly, Yin, Mao, ...), with the month of winter solstice as the next month, followed by ugly month, silvery month and the month before winter solstice as the sea month. Taking February as the first month of the year is called "Jianzi", and so on. According to some historical records, the Xia Dynasty built the Yin Dynasty, the Shang Dynasty built the ugliness, the Zhou Dynasty built the Zi Dynasty, and the Qin Dynasty built the sea. The sea was still built in the early Han Dynasty, and it was rebuilt in the first year of Emperor Wu of Han Dynasty (A.D. 104). Since then, although the calendar has changed many times, Yin Jian has never changed (except for a few short years when Wu Zetian adopted Zhou Zheng). From Yin Jian's point of view, Xia Zheng is used in calendars from taichu calendar in Han Dynasty to Constitution in Qing Dynasty, which can be called Xia calendar, but it doesn't mean that all other elements in the calendar belong to Xia Dynasty. In this way, "summer calendar" has become a class name in the calendar, not a proper name of a calendar.

As for the "old calendar", it was used after 19 1 1 year. 19 1 1 After the revolution in, the government announced the adoption of the Gregorian calendar. Compared with this new method, people call the "current constitutional calendar" used in the Qing Dynasty the old calendar.

The origin of the name "Lunar Calendar". There are twenty-four festivals in the traditional calendar of Han nationality, but there are no complete names of twenty-four festivals in the western calendar, only the winter solstice, summer solstice, vernal equinox and autumn equinox. The twenty-four solar terms originated from the ancient Han nationality, and they are of great significance to agricultural production, so the old calendar is often called the "lunar calendar". These are the names of folk customs.

3. Gregorian calendar and Gregorian calendar

What is the solar calendar? It is based on the apparent movement period of the sun, that is, the movement period of the earth around the sun, so it is called solar calendar, or solar calendar for short. Every calendar year is similar to the Tropic of Cancer, and the month and date in each calendar year are in good agreement with the position of the sun on the ecliptic. For example, the vernal equinox is always on March 2 1 or 22, which won't make much difference. Since the 12 division of a tropical year is about 30.5 days (30.4368 days), which is about two months, the Gregorian calendar also divides a year into 12 months. In fact, the so-called "moon" in the Gregorian calendar is just a hollow name that has nothing to do with the moon, and has nothing to do with the moon's changing cycle. According to the date of the solar calendar, we can't know the first and second chords of the moon, but according to the month of the solar calendar, we can see the changes of the four seasons more accurately than the combined calendar of Yin and Yang.

At present, the Gregorian calendar of all countries in the world is a kind of solar calendar, so it is not wrong to call the Gregorian calendar the Gregorian calendar. However, we should know that the solar calendar is a class name, not a proper name, and it cannot be said that the solar calendar is the Gregorian calendar. Because ancient Egypt also used the Gregorian calendar, julian calendar and Gregorian calendar in ancient Rome were also Gregorian calendars. The Gregorian calendar (or Gregorian calendar) is what we now call the Gregorian calendar. Gregorian calendar is the name given by people in China. There is no corresponding English word in the Chinese-English dictionary, only "Gregorian calendar". Although the Gregorian calendar does not have the name of the twenty-four solar terms, there are fixed months in the Gregorian calendar, and the difference between fixed days and years is at most one or two days. But in the lunar calendar and Tibetan calendar, a festival may be at the beginning, middle and end of the month, and there is no fixed date. Therefore, it is wrong to say that the 24 solar terms are the characteristics of the lunar calendar, and they should belong to the solar calendar in the lunar calendar and Tibetan calendar, because they are determined according to the position of the sun on the ecliptic.