What is it that there are two Spring Festival in 2262?

Everyone knows that there is a leap month in the lunar calendar. For example, on a lunar birthday, there will be a situation of "having two birthdays" a year. So how did leap years and leap months come about? Why did the leap first month appear in 2262? Let Alberta tell you more about it.

Calendar is made according to the law of phase change in the sky, and the main reference objects are the sun and the moon. If a calendar is made according to the changing law of the sun, it is called a solar calendar; if a calendar is made according to the changing law of the moon, it is called a lunar calendar.

The Gregorian calendar we usually use is the solar calendar, and the lunar calendar we use is neither the solar calendar nor the lunar calendar, but the yin-yang calendar, which sounds a bit strange. In fact, the lunar calendar combines all the advantages of the solar calendar and the lunar calendar and is the most advanced calendar. The biggest drawback is that it is complicated and difficult to remember!

Before we talk about the calendar, we need to make a time standard, and set a day and night cycle on the earth as 24 hours, that is, a day is 24 hours; There is an error in the day-night cycle, and now the world uses a more accurate atomic clock to define time.

solar calendar

The solar calendar is also called the solar calendar, and it takes 365.2422 days for the earth to make a circle around the sun, so a year in the solar calendar is defined as 365 years.

Rule number one: once every four years.

In order to compensate for the extra 0.2422 days every year, one day is added every four years, and there are 366 days in this year, which is called leap year.

Rule 2: Don't jump for a hundred years, and moisten again for 400 years.

But we calculate 0.2422*4=0.9688 days, and if we compensate for one day, we actually compensate more. In order to subtract the extra 1-0.9688=0.03 12 days every four years, we added a one-hundred-year leap and re-moistened it for 400 years.

After adding Rule 2, the calendar error becomes 0.0312 *100-3 = 0.12 days every 400 years, which is long enough. To eliminate the error of 0. 12 days, it is necessary to add additional rules in a longer period of time, which will not be used for thousands of years.

For the Gregorian calendar, the extra day in leap year is added to February, with 28 days in normal year and 29 days in leap year, which is also quite convenient to remember.

traditional Chinese calendar

The moon rotates around the earth, and the period of revolution and rotation period of the moon are equal, both of which are 27.32 days; However, as the earth revolves around the sun, the phase transition period of the moon lags behind the rotation period of the moon. According to the following figure, the lag time θ≈2.2 1 day can be obtained:

Then the change period of the moon phase is 27.32+2.2 1=29.53 days, and the lunar calendar reflects the change of the moon phase. Therefore, there are 29 days in the middle and small months of the lunar calendar and 30 days in the big month, which are used to divide the moon phase cycle equally.

lunisolar calendar

The lunar calendar has a very big shortcoming. There are 29.5* 12=354 days in a year in the lunar calendar, which is 1 1 many days less than that in period of revolution. If the lunar calendar is always used, in a few years, the changes of the four seasons of the lunar calendar will be completely chaotic, so the ancients in China invented the lunar calendar.

The lunar calendar has the advantages of both the solar calendar and the lunar calendar, and can reflect the changes of the four seasons and the phases of the moon. Because the lunar calendar is almost less 1 1 day than the solar calendar, it will take some time to add a lunar month to the lunar calendar.

Before the Qing Dynasty, the lunar calendar adopted "the seventh leap month in nineteen years", that is, leap months appeared in seven years every nineteen years, because the lunar calendar lacked 1 1 day and 19 by 209 days each year, and 209 days could be distributed in seven lunar months (7 * 29 = 203

There are high-order decimals in lunar months, so there will be great errors in the seven-leap-month method which has been going on for 19 years; During the Chongzhen period of the Ming Dynasty, Tang Ruowang, a western missionary, came to China and introduced a more accurate Gregorian calendar to the west. After the work of He Xu, the lunar leap method was changed to "neutral leap method", which has been used ever since, and the accuracy of the lunar calendar has been greatly improved.

Non-neutral leap month method

To understand the law of lunar leap month, we need to know what the 24 solar terms are.

The 24 Solar Terms

The earth revolves around the sun with an elliptical orbit, in which the winter solstice is perihelion and the summer solstice is apohelion; Define 15 per revolution of the earth as a solar term, with a total of 24 solar terms. Kepler's third law can be used to calculate the time points of solar terms in the solar calendar.

Because a month in the solar calendar is 365.2422/ 12 = 30.44 days, and a month in the lunar calendar is 29.53 days, with the passage of time, solar terms will lag behind in the lunar calendar, and solar terms are divided into solar terms and neutral gas, so one day, there will be a month without neutral gas in the lunar calendar.

Therefore, according to the lunar calendar, there is no leap year if there is 12 months, and there is a leap year if there is 13 months, so as to determine when to leap; Leap year refers to the neutral month from the winter of the current year to the first month in the future, and its name is "leap" before the name of the previous month. This is the "neutral month leap method". After this formulation, leap month can just make up for the error with the Gregorian calendar.

Leap in the first month of 2262

For example:

(1) Gregorian calendar 226 1 year 65438+February 22nd is the winter solstice, corresponding to the 30th lunar month, so there will be 13 months between the winter solstice in 2262, and 2262 is a leap month according to regulations;

(2) 65438+1October 20th in Gregorian calendar 2262 is a severe cold, corresponding to the 29th of the twelfth lunar month, so there is no leap in this month;

(3) February 19 in Gregorian calendar is moderate rain, corresponding to the 30th day of the first lunar month, so there is no leap in this month;

(4) March 2 1 in the solar calendar is the vernal equinox of neutral gas. If February comes after the first month, there will be no gas in February of the lunar calendar. According to the regulations, this month is a leap month, taking the leap of the previous month (the first month) as the first month of leap (abortion).

So in 2262, there were two first months. As for whether to celebrate the two Spring Festival, this is not the consideration of our generation.

The size of leap month does not follow leap month. For example, 20 17, leap June has 30 days, while in 2025, leap June has only 29 days. The lunar month is determined according to the phase of the moon. As for the size of leap or abortion, it needs to be determined according to the actual moon phase, so that a new moon will appear around the first day.

Supplementary knowledge:

(1) The essence of the twenty-four solar terms is formulated according to the solar calendar, which describes the changing law of the sun, so the twenty-four solar terms can well reflect the changes of the four seasons.

(2) The orbit of the earth's revolution is elliptical, the speed of the earth's revolution is faster at the perihelion of the winter solstice, and the time between two solar terms is shorter (14, 15 days), so the probability of no neutral month is very small, so it is very rare to have leap months in December, winter and January;

(3) The summer solstice moves slowly at the apohelion, and the time between two solar terms is long (15, 16 days), so there is no neutral month in a high probability, so leap months appear more frequently in April, May and June of the lunar calendar;

(4) There will be a month without neutral gas in about 2 years, and there will be 13 months between two winter solstices in leap years. Because the 24 solar terms are roughly evenly distributed, there will be no neutral gas for one month in that year.