When January 1, 0001?

The calendar is a system of group units from time consist of days, months, and years. Some calendars created from astronomical observations. For example, the day based on the rotation of the Earth on its axis, the year based on the revolutation of the Earth around the Sun, and the month based on the revolution of the Moon around the Earth. However, the people have many perceptions about when the January 1, 0001 had begun. They inferred that any three speculations about this such as the first time January 1 when 45 BC in Julius Caesar era, the birth of Christ, and the 1582 AD in Gregorian calendar.

 

 In 45 BC, Julius Caesar introduced the new calendar, solar based calendar that was a vast improvement on the ancient Roman calendar, which was a lunar system that had become wildly inaccurate over the years. The Julian calendar asked that the new year would happen with January 1, and within the Roman world, January 1 become the consistently observed start of the new year.

In medieval Europe, January 1 is adoption of the birth of Christ. This were considered from Pagan and Unchristian. Pagan and Unchristian believe January 1 as the beginning of the year. From the birth of Christ, the people can know about one BC and one AD, but nothing zero year.

In 1582, the Gregorian calendar restored from a perceive need to reform the method of calculating dates of Easter.Although most Catholic countries adopted the Gregorian calendar almost immediately, it was only gradually adopted among Protestant countries. The British, for example, did not adopt the reformed calendar until 1752. The Gregorian calendar today serves as an international standard of civil use.

Until now, all of people in the world still confuse about when January 1, 0001. They are just make nice speculation and guesses. Three nice speculations are in Julius Caesar era, the birth of Christ, and the 1582 AD in Gregorian calendar.