(1) Double spring years: 7 years in every 19 are double spring years.
China's calendar has been a kind of lunar calendar since ancient times. It is formulated in combination with the cycles of the sun and the moon.
A year is divided into 24 solar terms according to the movement of the sun and several months according to the movement of the moon.
The difference between the lunar calendar and the solar calendar is about 1 1 day. In order to solve the time difference between the lunar calendar and the solar calendar, the ancients added leap months to solve this problem.
In this way, one year in several years is 13 months, so every 19 years, there are seven years of double spring and seven years of no spring;
This is entirely an artificial adjustment of solar terms and phenology, and has nothing to do with the auspiciousness of weddings and funerals.
(2) leap month (lunar leap year): There will be 7 lunar leap years every 19.
The Gregorian calendar leaps every four years, while the lunar calendar 19 has seven leap years.
What is the origin?
The lunar calendar in China is a combination of yin and yang. In order to make up for the error of these 33 days and add a leap month to make up for it, the calculation method of 19 7 leap is adopted, which effectively avoids the strange things of wearing clothes in the first month and snowing in June.
So every 19 years, there will be 1 lunar month in 7 years.
There must be 24 solar terms in the solar calendar year, and the number of days in the lunar calendar is very different from that in the leap year. The coming Year of the Rat in 2020 is a leap year in the lunar calendar, with 25 solar terms.
Because beginning of spring is at the end of the year or the beginning of the year, under normal circumstances, the solar term in beginning of spring runs until the end of the previous year or spans to the beginning of the next year.
In 2020, the 1 1 of the first month of the Year of the Rat and the 22nd day of the twelfth month will be beginning of spring, showing a double spring phenomenon.