The ten days of158210.0510.0014 do not exist in history. Why?

Because there was a difference of ten days between the old calendar at that time and the actual time of the earth's revolution to vernal equinox, a new calendar, the Gregorian calendar, was issued at this time, and these ten days were skipped in figures to correct the date error.

A.D., the Gregorian era, was originally called the Christian era, also known as the Gregorian calendar or A.D., which is a kind of chronology that originated in western society. This is a calendar-Gregorian calendar, which was formulated by Italian doctor and philosopher aloysius Lilius after he reformed julian calendar. In A.D. 1582, the then Pope Gregory XIII approved the promulgation of this law.

At 1582, the vernal equinox of julian calendar (March 2 1 day) is 10 day different from the actual time when the earth revolves to vernal equinox. Therefore, when the Gregorian calendar began to be implemented, 1582, the day after 10, julian calendar was designated as Friday, 1582, 15, that is, 10 was deleted, but the original cycle of one week remained unchanged.

Extended data:

The calendar in People's Republic of China (PRC) (China) uses the year AD.

It was not until the eighth century that Christian countries in western Europe began to use the Gregorian calendar. Even the Pope always uses his rule to record documents for chronology. It was not until 1 1 century and14th century that the concept of AD became popular. It was also the result of European colonization that AD became the mainstream of the world. It also spread the Gregorian calendar and became an internationally recognized standard of chronology.

China had its own calendar as early as 4000 BC. Starting from the Chronology of the Yellow Emperor, in a long historical period, China used the "Chronology of Branches and Branches", that is, the ten-day trunk and the twelve-day branch were combined separately, and every 60 years was a cycle.

The calendar and calendar year of People's Republic of China (PRC) (China) adopts the Gregorian calendar of most countries in the world, but it still uses the traditional lunar calendar of China, which was decided by the first plenary session of the China People's Political Consultative Conference in September 1949. At the meeting, everyone agreed that the calendar system commonly used in most countries in the modern world should be adopted, that is, the year of New China should be the year of the West.

On September 27th, the second of the four resolutions adopted at the first plenary session of China People's Political Consultative Conference was: "The Gregorian calendar year is adopted in People's Republic of China (PRC)".

Since the starting point of the year is 1, most scientists who have a full understanding of the year and the most authoritative astronomical institutions in the world clearly support the statement that 2 1 century began at 200 1.

Baidu encyclopedia-A.D.