South County Fun (1.0) |
(Calendars) |
South County Fun (1.0) |
(Calendars) |
The Roman Calendar was "a mess". Year 47 BC was 355 days in length. Year 46 BC was 445 days in length. Julius Caesar introduced the Julian Calendar in 45 BC. It was used until the 1500's. Pope Gregory XIII, in a papal bull in Feb 1582, introduced the Gregorian calendar. It's leap year is every four years except when divisible by 100 unless also divisible by 400. ------------------------------------------------------ Dionysius (wrongly) fixed Jesus' birth with respect to Diocletian's reign in such a manner that it falls on 25 December 753 AUC (ab urbe condita, i.e. since the founding of Rome), thus making the current era start with AD 1 on 1 January 754 AUC. How Dionysius established the year of Christ's birth is not known (see section 2.10.1 for a couple of theories). Jesus was born under the reign of king Herod the Great, who died in 750 AUC, which means that Jesus could have been born no later than that year. Dionysius' calculations were disputed at a very early stage. When people started dating years before 754 AUC using the term ``Before Christ'', they let the year 1 BC immediately precede AD 1 with no intervening year zero. Note, however, that astronomers frequently use another way of numbering the years BC. Instead of 1 BC they use 0, instead of 2 BC they use -1, instead of 3 BC they use -2, etc. ----------------------------------------------------------- The concept of a year ``zero'' is a modern myth (but a very popular one). Roman numerals do not have a figure designating zero, and treating zero as a number on an equal footing with other numbers was not common in the 6th century when our present year reckoning was established by Dionysius Exiguus (see section 2.10). Dionysius let the year AD 1 start one week after what he believed to be Jesus' birthday. Therefore, AD 1 follows immediately after 1 BC with no intervening year zero. So a person who was born in 10 BC and died in AD 10, would have died at the age of 19, not 20. Furthermore, Dionysius' calculations were wrong. The Gospel of Matthew tells us that Jesus was born under the reign of king Herod the Great, and he died in 4 BC. It is likely that Jesus was actually born around 7 BC. The date of his birth is unknown; it may or may not be 25 December. ------------------------------------------------------------- In the historical system of dating, AD 1 is preceded by 1 BC; there is no year 0. In the astronomical system, AD 1 is designated +1; this is preceded by year 0, which is preceded by year -1. The historical system was introduced in the 16th century. However, the astronomical system was not introduced until the 18th century.
