Talk about calendars-calendars

Let's talk about the calendar. Why do we start with the lunar calendar? I won't tell you if you ask.

The lunar calendar is a traditional calendar and a great calendar. After reading the full text, I will understand how it works.

Lunar Calendar, also known as the lunar calendar, is an old calendar. Chinese People's birthdays, traditional festivals, and so on are arranged by calendar. However, the current birthday of a child seems to have been in the Gregorian calendar (also called the Gregorian calendar. First, it is easy to remember, because everyone lives on a calendar in normal times. Second, What constellation is popular now, And the constellation is something that has been passed by the West, westerners live in the Internet. Therefore, if you report a lunar New Year's birthday, the constellation is not the same as what people say.

Here, we have to explain some names. Don't bother! If it is too troublesome, let's look down, because this is not a simple thing.

Calendars are developed by the ancients by observing astronomical phenomena.

What is astronomical phenomenon? Here we are, that is, sunrise and sunset, lack of full moon. A scientific definition is called the distribution, movement, location, state, structure, composition, nature, origin, and evolution of celestial bodies ". There is a specialized discipline that studies these phenomena, called astronomy.

Of course, astronomy is so profound and far-fetched that if you are not interested, you do not have to go into it. Let's continue to talk about the calendar here and understand the things related to daily life.

In astronomy, there is a calendar called the Gregorian calendar, and a foreigner called the Gregorian calendar, which is actually the Gregorian calendar used in daily life and unified throughout the world.

Everyone knows that the Earth rotates for one day, and the revolution for one year. The Gregorian calendar is calculated based on the last half sentence. In astronomy, the year is called the year of return, or the year of the sun.

What's going on in the year of return? Let me hear it. (Calm, calm, and many concepts, and you have to overhead yourself -_-")

The earth's orbit around the Sun is an elliptic, and the plane of the elliptic is called a yellow track.

Taking the earth sphere as the center, imagine infinitely enlarging the earth, and you can get an imaginary sphere called the tiangular. As a matter of fact, the Dongdong ancestor of tianqiu has an image description: The sky is like a dome, covering the four fields. The "dome" here can be said to be the internal sphere of the celestial sphere you see.

The circle between the celestial sphere and the yellow track is called the yellow track.

The sun starts from the yellow road and returns to this point again. The time it passes is a year of return. One year of return = 365.2421990741 days = 365 days 5 hours 48 minutes 46 seconds.

Because a year of return is not an integer Day, it still carries a small tail, but cannot come out all day, and then it is set to 5 hours 48 minutes 46 seconds. So in the year of the year, the year of the leap game debuted, resolving this embarrassment.

It must be a normal year, 365 days a year. Then, we can combine the hours of the average year into one day, and add them to the year of 366. In this year, there will be 29 days, and there will be days in this year, this year, which is one day longer than the normal year, is called a leap year.

In this way, a leap year can be created every four years. For example, the year before, that is, the year 2008 is a leap year. If a leap year is used for four years, the year 2012 is also a leap year.

Is the calculation of a leap year just like this and so on? Of course not. Pay attention to the previous words, "Basic "! Right, that is, basic, which means that the following year is not a leap year.

The reason is to use data to speak. One year of return = 365 days, 5 hours, 48 minutes, 46 seconds. An average year, 5 hours, 48 minutes, 46 seconds, 4 years, 23 hours, 15 minutes, 04 seconds, 44 minutes, 56 seconds less than a day. In this way, there will be a different day in around 128. The direct result is that the time and season are not correct.

A simple way to divide the Four Seasons is to determine the sun's position on the yellow track. There are four points on the yellow track, namely the spring equinox, the summer solstice, the autumn equinox, and the winter solstice. when the sun is at these points, it indicates that the northern hemisphere is in the corresponding season.

When the error gradually accumulates, it will become clear that it is already in August. It is supposed that the childen pants and slippers should enjoy the ice and cold drinks outside, but the actual climate is just starting from Winter to spring, you can only wrap a cotton jacket at home. Because of the error, the sun is not at the corresponding point.

Therefore, after a series of calculations, scientists have obtained a method to determine the leap year, avoiding errors as much as possible.

Algorithm: The year that is a multiple of 4 or 400, but not 1900,100, 3200, or is a leap year.

Here, the Gregorian calendar is basically finished.