section_path: History
section_name: History
paragraph_text: History
  
  The first appearance of the term is in the treatise of a monk and priest, Georgios (AD 638–639), who mentions all the main variants of the "World Era" in his work. Georgios argues that the main advantage of the World era is the common starting point of the astronomical lunar and solar cycles, and of the cycle of indictions, the usual dating system in Byzantium since the 6th century. He also regarded it as the most convenient for the Easter computus. For the details see the section "Tabular Byzantine calendar" below. Complex calculations of the 19-year lunar and 28-year solar cycles within this world era allowed scholars to attribute cosmic significance to certain historical dates, such as the birth or the crucifixion of Jesus.
  
  This date underwent minor revisions before being finalized in the mid-7th century, although its precursors were developed c. AD 412. By the second half of the 7th century, the Creation Era was known in Western Europe, at least in Great Britain. By the late 10th century (around AD 988), when the era appears in use on official government records, a unified system was widely recognized across the Eastern Roman world.
  
  The era was ultimately calculated as starting on September 1, and Jesus was thought to have been born in the year 5509 since the creation of the world. Historical time was thus calculated from the creation, and not from Christ's birth as it was in the west after the Anno Domini system adopted between the 6th and 9th centuries. The eastern Church avoided the use of the Anno Domini system of Dionysius Exiguus, since the date of Christ's birth was debated in Constantinople as late as the 14th century.
  
  The Byzantine calendar was identical to the Julian calendar except that:
  
  The leap day of the Byzantine calendar was obtained in an identical manner to the bissextile day of the original Roman version of the Julian calendar, by doubling the sixth day before the calends of March, i.e., by doubling 24 February.
  
  The Byzantine World Era was gradually replaced in the Eastern Orthodox Church by the Christian Era (Anno Domini), which was utilized initially by Patriarch Theophanes I Karykes in 1597, afterwards by Patriarch Cyril Lucaris in 1626, and then formally established by the Church in 1728. Meanwhile, as Russia received Orthodox Christianity from Byzantium, it inherited the Orthodox calendar based on the Byzantine Era (translated into Slavonic). After the collapse of the Byzantine Empire in 1453, the era continued to be used by Russia, which witnessed millennialist movements in Moscow in AD 1492 (7000 AM). It was only in AD 1700 that the Byzantine calendar in Russia was changed to the Julian calendar by Peter the Great. It still forms the basis of traditional Orthodox calendars up to today. September AD 2000 began the year 7509 AM.