How to calculate leap month?

A leap month is a way to set a leap month in a calendar. In Asia (especially in China), leap month refers to one month added every leap year in the lunar calendar (in order to coordinate the contradiction between the tropic year and the lunar year and prevent the lunar year from being out of touch with the tropic year and the four seasons, 1 leap and 19 leap are set every two to three years). Sometimes, a leap month also refers to a month that includes a leap day in a leap year (especially in February of a leap year in the Gregorian calendar). A leap month is an additional month in every leap year. In the lunar calendar, the length of the first lunar month (29.5306 days) is the average of one month, which is 65438+February in the whole year, which is about 10 and 2 1 hour different from the tropic year (365.2422 days), so it is leap in turn, one month in three years, two months in five years and seven months in nineteen years. A leap month is called "leap month" after a certain month. For example, the last leap month in 2009 was May (June 23rd, 2009-July 2nd, 20091), and the upcoming leap month of 20 12 was April (20 12). What we usually call "leap year" is actually an approximation. Then there are 365 days in a year, which is O.2422 days different from the actual year, so four years later, it is nearly one day less than the actual year. In order to make up for this difference, the calendar stipulates that four years is a leap year, that is, a year divisible by four is a leap year, and additionally stipulates that every century year (a year with two zeros at the end) must be divisible by 400 to be a leap year. For example, 1996 is a leap year, and 2000 is also a leap year, but 1700 is not. The leap year in the solar calendar has 29 days in February, the leap day is February 29 and the leap year in the solar calendar has 366 days. In other words, February in a leap year in the solar calendar is not called leap February, and leap months are unique to the lunar calendar. Now let's talk about "leap month". Leap moon refers to a phenomenon in the lunar calendar. The lunar calendar arranges the big moon and the small moon, that is, the moon, according to the full and short moon. The length of a moon is 29.5306 days, which is the cycle of the moon's profit and loss. According to the lunar calendar, there are 30 days for the big moon and 29 days for the small moon, and a year is 12 months * * 354 days. Lunar month has no seasonal significance, so its length is 29.5306× 12=354.3672 days, which is less than 365.2422 days in the tropic year (that is, near 1 1 day) 10.88 days, and 0.9/kloc per month. The difference between solar calendar year and year is 1 1 day. Only after 17 will the date of the lunar calendar be reversed in the same season. For example, a year's New Year is spent in the snow, and a new year comes after 17. The use of such a calendar naturally cannot meet the needs of agricultural production, so the lunar calendar in China has been in parallel with the 24 solar terms since the Qin and Han Dynasties, and the 24 solar terms are used to guide agricultural production. Many people misunderstand the lunar calendar in China and often confuse it with the lunar calendar. There are three calendars in the world: one is the solar calendar, in which the time for the earth to go around the sun is one year, and the number of months and days in a year can be specified artificially; One is the lunar calendar, in which the time for the moon to circle the earth is one month, and only a few months in a year can be designated artificially; The third is the yin-yang calendar, that is, the average time for the moon to orbit the earth is January, but by setting leap months, the average number of days in a year is equal to the average time for the earth to orbit the sun, such as the lunar calendar and Tibetan calendar in China. Therefore, the lunar calendar in China is not a lunar calendar, but a combination of yin and yang. The lunar and solar elements in the lunar calendar have their own uses. The lunar calendar can indicate the moon's profit and loss, and can also predict the tides. The solar calendar is more useful. Twenty-four solar terms are a great invention in ancient China. It shows the position of the earth in orbit, reflects the annual apparent movement of the sun, and is most suitable for guiding agricultural activities. Therefore, the traditional lunar calendar in China is called the lunar calendar. Therefore, the lunar calendar is different from the lunar calendar, and it is not appropriate to call the lunar calendar the lunar calendar. The sun and the moon are calendars that people hang in the sky. Year after year, the earth revolves around the sun, and everything on the earth lives and multiplies in the cycle of the sun and the moon. If the lunar year consists of thirteen lunar months, the length is 29.5306× 13=383.8978 days, which is more than the tropic year 18 days. If the calendar is made according to the above regulations, there will be a strange phenomenon that the weather is inconsistent with the calendar and the time order is disordered and reversed. This is the contradiction. In order to overcome this shortcoming, our ancestors explored the method of "leap month" on the basis of astronomical observation, ensuring that the first month to March is spring, April to June is summer, July to September is autumn, and October to December is winter, and at the same time ensuring that the first year of the lunar calendar is in late winter and early spring (all above refer to lunar season). The calculation method of editing this paragraph is leap month. The mid-year month of the lunar calendar is based on the length of 29.5306 days in the first lunar month, so the big month is 30 days and the small month is 29 days. In order to ensure that the first day of each month (the first day) must be a new moon, the arrangement of large and small months is not fixed and needs to be determined through strict observation and calculation. Therefore, it is common for the lunar calendar to be big and small for two consecutive months, and even there are rare exceptions such as March and April of 1990. September, 10,1month and1February are big for four consecutive months. So how often do you add leap months? The best way is to find the least common multiple of the number of days in the tropic year and the number of days in the lunar month: we hope that the number of days in the tropic year is equal to the number of days in the lunar month, that is, there should be an equation: m×365.2422=n×29.5306. In this equation, we can't work out M and N directly, but we can work out their proportions: the approximate value of this proportion is: in these fractions, the numerator represents the number of years of the tropic of cancer. For example, the sixth fractional formula 19/235 =19/(19×12+7) means that seven leap months must be added to19 tropical year. 19 tropical year plus 7 leap months: 19 tropical year =19× 365.2422 = 6939.6018 (days). A lunar month has 29.5306 days, and 235 lunar months = 235 × 29. The contradiction only eliminates one difference: 6939.438+00-6939.438+08 = 0.092 (days)-that is, more than 2 hours and 9 minutes, which is accurate enough. Therefore, the lunar calendar adopts the method of 19 plus 7 leap months, that is, the "19 7 leap month method", which well coordinates the return year and the lunar year, so that the New Year's Day (Spring Festival) of the lunar calendar is always kept in the late winter and early spring. The ancients called 235 new moons "leap weeks". The method of placing leap in the lunar calendar can make the average length of the lunar year close to the tropic year. The moon in the lunar calendar has distinct moon phase characteristics, which keeps the best characteristics of both the solar calendar and the lunar calendar. At present, the method of setting leap is between two winter solstice. If it is only 12 months, it is not a leap; if it is 13 months, it is a leap. The leap month begins on the "winter solstice". When there is no "neutral spirit" in the first month, this month is a leap month, and its name is to add the word "leap" before the previous month. What month is the lunar leap month? It depends on the 24 solar terms in a year. In the China lunar calendar, 24 solar terms are divided into 12 solar terms and 12 neutral terms. The lunar calendar takes the moon as the cycle (lunar calendar), and the December calendar is about 354 days. Combined with the almanac (solar calendar), the almanac is compiled according to the four-season cycle formed by the revolution of the earth. The monthly calendar is shorter than the annual calendar by 1 1 day. Therefore, it is necessary to add 7 leap months every 19 years to make up for the error. Which month is a leap month depends on 24 solar terms. Lunar months usually include a solar term and a neutral atmosphere, such as the vernal equinox. If a lunar month has only solar terms and no neutral atmosphere, the calendar will take that month as the leap month of last month. Take 2006 as an example. After July of the lunar calendar, there happens to be a month with only solar terms and no neutral atmosphere, so we set leap July to adjust the error. The date of the twenty-four solar terms of the lunar calendar is postponed month by month, so in some lunar months, the gas falls at the end of the month, and it will be out of gas next month. Generally, there will be a month without gas every two years, which coincides with the year when leap months are needed. Therefore, the lunar calendar stipulates that non-neutral months are leap months. For example, May 2 1 of 20065438 and April 29 of the lunar calendar are full of vitality, and June 2 1 a month later, the first day of the fifth lunar month, is the next summer solstice, this month (20065438-May 23+0-20065438+) because it follows April. Edit the leap month list in this paragraph from 1645 to 2796, according to 1645 leap May 1648 leap April165/leap first month 1653 leap June/kloc-0. 8+0 leap August 1664 leap June 1667 leap April 1670 leap February 1672 leap July 1675 leap may 1678 leap March/. 89 leap march 169 1 leap july 1694 leap may 1697 leap march 1699 leap july 1702 leap june 1705 leap. 8+03 leap may 17 16 leap March 17 18 leap August 172 1 leap June 1724 leap April/kloc-. 8+0737 leap September 1740 leap June 1743 leap April 1746 leap March 1748 leap July 175 1 leap may/kloc-0. 1765 leap February 1767 leap July 1770 leap may 1773 leap March 1775 leap October 1778 leap June178. 9 leap may 1792 leap April 1795 leap February 1797 leap June 1800 leap April 1803 leap February 1805 leap July/kloc-. +04 leap February 18 16 leap June 18 19 leap April 1822 leap March 1824 leap July 1827 leap may/. Leap April 184 1 leap March 1843 leap July 1846 leap May 1849 leap April 185 1 leap August/kloc. 1865 leap may 1868 leap April 1870 leap October 1873 leap June 1876 leap may 1879 leap March1879 leap March. Leap February 1892 leap June 1895 leap May 1898 leap March 1900 leap August 1903 leap May 1906 leap April/kloc- Leap May 19 17 leap February 19 19 leap July 1922 leap May 1925 leap April 1928 leap February/KLOC. July 194 1 leap June 1944 leap April 1947 leap February 1949 leap July 1952 leap may 1955 leap 3. 966 leap March 1968 leap July 197 1 leap May 1974 leap April 1976 leap August 1979 leap June1988. 438+0993 leap March 1995 leap August 1998 leap May 200 1 leap April 2004 leap February 2006 leap July 2009 leap May 20 12 leap April 201. 5 leap 2028 leap June leap May 203 1 leap March 2033 leap winter month 2036 leap June 2039 leap May 2042 leap February 2044 leap July 2047 leap May 2050 leap March 2052 leap August 2055 leap June 2058 leap April 2006/kloc-0 Month 2069 leap April 207 1 leap August 2074 leap June 2077 leap April 2080 leap March 2082 leap July 2085 leap May 2088 leap April 2090 leap August 2093 leap June 2096 leap April 2099 leap February 210/kloc 2 107 leap April 2 109 leap September 212 leap June 2 1 15 leap April 2 1 18 leap March 2 Dongyue 2 13 1 leap June 2 134 leap May 2 137 leap February 2 139 leap July 2 142 leap May 2 145 leap 4. 056 leap March 2 158 leap July 2 16 1 64 leap April 2 166 leap October 2 169 leap June 2179. 5438+083 leap April 2 186 leap February 2 188 leap June 2 19 1 leap may 2 194 leap March 2 196 leap July 2/kloc. 22 13 leap March 22 15 leap July 22 18 leap May 22 1 leap April 2223 leap September 2226 leap July 2229 leap May 2232 leap March 2234 leap August 2237 leap May 2244. 25 1 leap March 2253 leap July 2256 leap June 2259 leap May 2262 leap January 2264 leap July 2267 leap May 2270 leap March 2272 leap August 2275 leap June 2278 leap April 228 1 leap February 2283 leap June 2283. 438+0 leap July 2294 leap June 2297 leap April 2300 leap February 2302 leap June 2305 leap May 2308 leap March 23 10 leap July 23 13 leap June 23 16 leap April 23/kloc- 7 leap March 2329 leap August 2332 leap June 2335 leap April 2338 leap March 2340 leap July 2343 leap May 2346 leap April 2348 leap August 235 1 leap June 2354 leap May 2357 leap 1 month 2359 leap July 2366. Leap June 2373 leap May 2376 leap February 2378 leap July 238 1 leap May 2384 leap April 2386 leap1October 2389 leap June 2392 leap April 2395 leap February 2397 leap June 2400 leap May 2403 leap March 2400. +0 leap may 24 14 leap February 24 16 leap July 24 19 leap may 2422 leap March 2424 leap August 2427 leap June 2430 leap April 2433 leap March 2435 leap July 2438 leap May 244/. 9 leap May 2452 leap March 2454 leap August 2457 leap May 2460 leap April 2462 leap August 2465 leap June 2468 leap May 247 1 leap March 2473 leap July 2476 leap May 2479 leap April 248 1 leap/kloc. Month 2492 leap July 2495 leap May 2498 leap April 2500 leap 1 October 2503 leap June 2506 leap May 2509 leap February 251leap July 25 14 leap May 25/kloc-0. 2530 leap July 2533 leap June 2536 leap April 2539 leap January 254 1 leap July 2544 leap May 2547 leap March 2549 leap July 2552 leap June 2555 leap April 2557 leap August 2560 leap July 2563 leap May 2566 leap April 2568. 0 leap June 2574 leap April 2576 leap September 2579 leap June 2582 leap April 2585 leap March 2587 leap July 2590 leap May 2593 leap April 2595 leap1October 2598 leap July 260 1 leap May 2604 leap March 2604. Month 26 14 leap winter month 26 17 leap June 2620 leap May 2623 leap March 2625 leap August 2628 leap June 263 1 leap May 2634 leap January 2636 leap July 2639 leap May 2642 leap March 2644 leap. Leap February 2655 Leap July 2658 Leap May 26 1 Leap March 2663 Leap July 2666 Leap June 2669 Leap April 2672 Leap March 2674 Leap July 2677 Leap May 2680 Leap March 2682 Leap July 2685 Leap June 2688 Leap April 269/kloc 2696 leap May 2699 leap March 270 1 leap August 2704 leap June 2707 leap April 27 10 leap March 27 12 leap July 27 15 leap May 27 18 leap 4. 5438+0 leap July 2734 leap May 2737 leap April 2739 leap September 2742 leap June 2745 leap May 2748 leap February 2750 leap July 2753 leap June 2756 leap April 2758 leap August 276 1 leap June 2764 leap May 2767 leap 3. 2775 Leap March 2777 Leap August 2780 Leap June 2783 Leap May 2786 Leap March 2788 Leap July 279 1 Leap June 2794 Leap March 2796 Leap August It is predicted that there will be an unprecedented leap December in 3358! Some years should be staggered, such as 1832, 185 1 and18702 June 19).