Why does the weather change with the calendar?

It seems that people do not know much about calendars. To solve the landlord's problem, the most straightforward answer is "Qingming" (that is to say, including all the 24 solar terms), which has never been necessarily related to the lunar calendar, but is directly related to the solar calendar.

Of course, the earliest calendar in China is the lunar calendar. In fact, the most appropriate statement is the lunar calendar, because it is based on the "lunar calendar", that is, the sunny and cloudy days of the moon. But, of course, people will find that it is not very accurate to measure the four o'clock in a year by lunar calendar, and there are often some errors before and after (that is, the errors between lunar calendar and solar calendar can be seen now), which seriously affects agriculture, so calendars must be developed.

Of course, we can't reinvent the calendar, so we have the 24 solar terms in "Shenkuo". In fact, at that time, China's calendar was already very developed. In the Ming Dynasty, I forgot a name, and it was basically determined that a year was about 365 days, 5 hours and 56 minutes. Of course, people use fractions, which basically coincide with the time when the earth goes around the sun.

Let's go back to 24 solar terms. In fact, we are not only concerned about Qingming, but also find that a fairly stable month has two solar terms, which are generally 5/6 and 2 1/22. If you only pay attention to Qingming, you will also find that Qingming is always on April 5 or 6 every year. This shows that solar terms and solar calendar use a set of systems.

So the 24 solar terms became the main basis of ancient farming, but because the solar terms were not necessarily related to the date of the lunar calendar, the ancients didn't know there was a solar calendar at all, so I will introduce a word called "imperial calendar" here. Please note that many people may think that the "yellow calendar" is a "yellow calendar", but they don't know what an imperial calendar is. It is precisely because of the difference between solar terms and lunar calendar (the prevailing calendar) that in order to enable people to sow and harvest at the right time, there must be such an institution-Qin, which studies the calendar of each year and then presents it to the emperor before the arrival of the next year, and the emperor announces the time and things of the next year, so it is time to sow or harvest. This is the origin and purpose of the real imperial calendar.