He included all the rules for the calculated calendar epoch and their scriptural basis, including the modern epochal year in his work, and establishing the final formal usage of the anno mundi era.The first year of the Jewish calendar, Anno Mundi 1 (AM 1), began about one year before Creation, so that year is also called the Year of emptiness.Most of the 1,732-year difference resides in numerical discrepancies in the genealogies of the two versions of the Book of Genesis.Patriarchs from Adam to Terah, the father of Abraham, are said to be older by as much as 100 years or more when they begat their named son in the Greek Septuagint than they were in the Latin Vulgate (Genesis 5; Genesis 11) or the Hebrew Tanakh (Gen 5; Gen 11).The Alexandrian Era of 25 March 5493 BC was adopted by church fathers such as Maximus the Confessor and Theophanes the Confessor, as well as chroniclers such as George Syncellus.
In the course of their studies, men such as Tatian of Antioch (flourished in 180), Clement of Alexandria (died before 215), Hippolytus of Rome (died in 235), Sextus Julius Africanus of Jerusalem (died after 240), Eusebius of Caesarea in Palestine (260-340), and Pseudo-Justin frequently quoted their predecessors, the Graeco-Jewish biblical chronographers of the Hellenistic period, thereby allowing discernment of more distant scholarship.
He [the questioner] thought that Rav Nahman wanted to dispose of him anyhow, but when he went and studied it thoroughly he found that it is indeed taught [in a Baraita]: In the Diaspora the Greek Era alone is used. In the 8th and 9th centuries AD, the center of Jewish life moved from Babylonia to Europe, so calculations from the Seleucid era "became meaningless".
being the number of years since the AD 70 destruction of the Second Temple, and the number of years since the Creation year based on the calculation in the Seder Olam Rabbah of Rabbi Jose ben Halafta in about AD 160. The new system reached its definitive form in AD 1178 when Maimonides completed the Mishneh Torah.
Annianus of Alexandria however, preferred the Annunciation style as New Year's Day, 25 March, and shifted the Panodoros era by about six months, to begin on 25 March.
This created the Alexandrian era, whose first day was the first day of the proleptic This system presents in a masterly sort of way the mystical coincidence of the three main dates of the world's history: the beginning of Creation, the Incarnation, and the Resurrection of Christ.