Seleucid era
The Seleucid era or Anno Graecorum (literally "year of the Greeks" or "Greek year"), sometimes denoted "AG", was a system of numbering years in use by the Seleucid Empire and other countries among the ancient Hellenistic civilizations. It is sometimes referred to as "the dominion of the Seleucidæ," or the Year of Alexander. The era dates from Seleucus I Nicator's re-conquest of Babylon in 312/11 BC after his exile in Ptolemaic Egypt, considered by Seleucus and his court to mark the founding of the Seleucid Empire. According to Jewish tradition, it was during the sixth year of Alexander the Great's reign that they began to make use of this counting. The introduction of the new era is mentioned in one of the Babylonian Chronicles, the Chronicle of the Diadochi.
Two different uses were made of the Seleucid years:
The natives of the empire used the Babylonian calendar, in which the new year falls on 1 Nisanu (3 April in 311 BC), so in this system year 1 of the Seleucid era corresponds roughly to April 311 BC to March 310 BC. This included the Jews, who call it the Era of Contracts. It is used in the Jewish historical book, now "deuterocanonical", 1 Maccabees, in 6:20, 7:1, 9:3, 10:1, etc.
