Introduction to Julian day

This calendar has been widely used by astronomers, historians and chronologists. This kind of calendar is the most effective tool to study ancient history and ancient calendar. It has many uses, such as calculating the total number of days of major events, the total number of days of large-scale project construction, and the number of days when banks calculate interest on a daily basis. As long as the calculated Julian days at the starting point are subtracted from the Julian days at the end point, the total number of days from the starting point to the end point can be obtained. This kind of calendar for recording days is irreplaceable by other calendars in many aspects. The general method of calculating Julian day is to look up the table in the book, which lists the number of Julian days in each century, year and month. Users can look up the number of Julian days in the table as needed. In the Middle Ages, it was not known whether the number of Julian days per year was correct. I don't doubt that the number of Julian days in the table in the book is wrong, but I found that the number of Julian days in different versions of the book in the same year is different, so there must be a book with the number of Julian days wrong. Even if we know that the number of Julian days in a book is wrong, it is difficult to know which book has the wrong number of Julian days. This problem has always been a problem. I began to study this problem a few years ago. After several years' research, I not only found out the right and wrong of Julian days in two books, but also found a set of formulas to accurately calculate the number of Julian days in any year, and how to check the right and wrong of Julian days in the books. Let me elaborate on my argument and the way to check the right and wrong of Julian Day in books. HSMQ0

I have studied astronomical calendars for more than ten years. I have two books about calendars in my hand, one is the Perpetual Calendar by Mr. Ju An Deyu, and the other is 1972 [China Astronomical Calendar]. However, the number of Julian days listed in these two books is different. I will list the differences between the two books as follows: [Part]

[China Astronomical Almanac] [Perpetual Almanac]'

Julian day

1 50065438+1 October1D2268932150065438+1Oct/D2268933.

1 60065438+1 October1day 2305447160065438+1October1day 2305448

1 700 65438+1 October1DY2341971700 65438+1October/DY234/kloc-0.

1 80065438+1 October1D2378495180065438+1Oct/D2378496.

190011October1501919001October/kloc-0.

2000 65438+1October 1 245 1544 2000 65438+1October1545

These are the number of Julian days in each century in the two books. [China Astronomical Calendar] The number of Julian days in each century is one day less than that in the perpetual calendar. Who is right and who is wrong? This problem has been in my mind for several years, and the vast number of astronomy and calendar lovers must be very interested in it. A few years ago, I couldn't judge and calculate whether it was right or wrong. After several years of research, I invented a perpetual calendar, which can not only calculate the annual trunk branch, monthly trunk branch, daily trunk branch, monthly trunk branch and 24 solar terms, but also accurately calculate any age, any year, month and day. Thanks to this formula, I finally solved my doubts. I have used the calculation formulas in two books many times every century on 1 month 1 day. One of them checked whether my calculation formula was correct, and the other looked at Julian Day in the book. After verification, it is proved that my calculation formula is very accurate, simple and fast. In the process of verification, I found that both almanac have problems. There are mistakes in the number of days of Julian Day in both books. I will list some mistakes in 1972 [China astronomical almanac] and [perpetual calendar] and talk about my arguments and arguments. Moreover, I will work out the Julian day, the Japanese branch and the week of each century after A.D. for the reference of fans. And the method of correctly judging the number of Julian days in each era.

A, 1972 [astronomical almanac of China] 1000 to 2000 1 month/day, in which 1 000 to 1600,/kloc-.

B, [perpetual calendar] The number of Julian days in each century from 1 month 1 day before 1600 is correct, while in the three centuries, 1700, 1800 and 1900 are correct.

C, the annual calendar spectrum 】 【; 1 to 99 has many errors.