Why is there a difference between the lunar calendar and the solar calendar?

The so-called lunar calendar and solar calendar are two different calendar calculations, and their reference objects are different. Lunar calendar, also called lunar calendar, is a calendar handed down from ancient times in China. It is a calendar based on the law of the moon's rotation around the earth, that is, on the change of the moon's cycle. Each calendar month of the lunar calendar is approximately equal to the new moon, and any date of each month contains the meaning of the moon phase. The calendar year is 12 months, the average year is 354 days, and the leap year is 355 days. Every 30 years, 1 1 year is a leap year, and other 19 years are normal years. The pure lunar calendar can accurately reflect the change of the moon phase, but it can't judge the season according to its month and date, because its Gregorian calendar year has nothing to do with the tropic year.

The Gregorian calendar, also known as the Gregorian calendar, is based on the movement cycle of the earth around the sun. The Gregorian calendar year is approximately equal to the tropic year, one year 12 months. This "month" has nothing to do with the first lunar month. The month and date of the solar calendar are very consistent with the position of the sun on the ecliptic. According to the date of the solar calendar, we can clearly see the changes of cold and warm seasons in a year. But every month, you can't see the new moon, the new moon, the new moon. This is a popular calendar in the world today.

Yes, there are about eleven days a year. According to the lunar calendar, we will celebrate the Spring Festival in summer in less than five years. However, this did not happen. This is a kind of calendar calculation of "harmony of yin and yang" initiated by our clever ancients, which is called "Yin and Yang Calendar", which is what we often call "Lunar Calendar"!

The emergence of the "lunar calendar" also led to our common "leap month". China adopts the method of "seven leaps in nineteen years". That is, the total time of 19 solar years is basically the same as that of 19 moon years plus 7 lunar months, so there are 12 normal years (12 months) and 7 leap years (13