With the coming of the year 2000 A.D., it is an opportune time to understand our calendar. The Oxford Dictionary gives one definition of a calendar as a "system fixing a year's beginning, length and subdivision." It is generally accepted, but incorrectly, that New Year's day 2000 marks the two thousandth anniversary of the birth of the Christ child in Bethlehem, an event that was the start of the Christian era.
The ancients were aware that the seasons were regular and found that it took about 365 days for the complete cycle, or year, to repeat. They were unaware that the Earth spun daily on its axis, and that a year was defined by an annual orbital journey round the sun. Much later it was realised that the seasons are due to the Earth's axis being inclined relative to the earth's solar orbit. Without this inclination each day would consist equally of dark and light, as at the two equinoxes.
The calendar in use 2000 years ago was a development of the ancient Egyptian system which recognised twelve months of thirty days plus an extra five days at the end of the year. The Roman calendar was based on the legendary founding of Rome by Romulus and Remus in the year now called 753 B.C. Julius Caesar is credited with introducing the "leap year" system in 46 B.C., when an extra day was added at the end of the Roman year, after the last day of February.
This was the first attempt to reconcile an astronomical year to a practical month and week system. However, four was considered an unlucky number and the priests of the day applied the correction every three years, with the result that the year 8 B.C. began three days late. This error was corrected by Augustus Caesar who decreed that until the year 8 A.D. there were to be no more leap years. The Roman calendar, thus corrected, was known as the Julian calendar and was observed without further change until the reform of Pope Gregory XIII in 1582.
The Anno Domini system in use today was devised about the year 530 A.D. by a monk named Dionysius Exiguus "Denis the Little" from Scythia in south west Russia. Dionysius was concerned with the correct calculation of the date of Easter (a lunar dependent event) and the calendar in use at that time was measured from the start of the reign of emperor Diocletian about 250 years earlier. Dionysius through careful calculation deduced that it was 532 years from the birth of Christ. Since easter commemorates the most important event in the Christian year, Dionysius believed it more appropriate to date the years from a Christian standpoint. So was born the Anno Domini system. The system found a champion in the eighthcentury historian, the Venerable Bede, who used it in his Ecclesiastical History of the English People.
However, historians and theologians now agree that Dionysius must have made an error in his estimate. Historical evidence shows that the birth of Christ could not have occurred later than 4 B.C. as that was the date Herod the Great is known to have died. Similarly astronomical evidence shows that there was a triple conjunction of the planets Jupiter and Saturn in 7 B.C. This event would have been of great significance to the astrologers of the time because the two planets approached one another in the sky three times in a period of six months. These planetary conjunctions can be associated with the Star of Bethlehem. The evidence therefore suggests that the nativity actually took place in the year 7 B.C. so the two thousandth anniversary actually took place some years ago!
Most of the people adopted the Gregorian calendar in 1582, but England did not. While the English astronomers recommended the proposed change, the decision was clouded by political considerations. In short, the conflict of Henry VIII and the Roman Church was still fresh in the politicians' minds and they were not willing to adopt what, after all, was considered to be a Popish initiative.
Eventually England followed suit and changed the Julian for the Gregorian calendar in 1752. Due to the extra delay, it was then necessary to delete eleven days. September 2nd 1752 was followed by September 14th. Near riots greeted the proposals with the slogan "Give us back our eleven days!" At the same time, new Year's Day was changed to 1 January from 25 March (Lady Day). It is worth noting that a pro Dickensian Scrooge, prior to 1752 could have avoided Christmas altogether by travelling, say, from London on the 20th December, to Paris where the date would have been 31st December. Use of the Julian calendar still survives in the British tax year which ends on April 5th, derived from March 25th plus eleven days.
Last, some people argue that the new millennium will not start until January 2001. They are quite correct, and the reason is that there is no year zero A.D. The Anno Domini system of date started at year one.
John Elsworth