September (pronunciation) is the ninth month of the year in the Gregorian Calendar and one of four Gregorian months with 30 days. In Latin, septem means "seven" and septimus means "seventh"; September was in fact the seventh month of the Roman calendar until 153 BCE, when the first month changed from Kalendas Martius to Kalendas Januarius. In the Northern hemisphere, the beginning of the meteorological autumn is 1 September.
44 BC – Pharaoh Cleopatra VII of Egypt declares her son co-ruler as Ptolemy XV Caesarion. 44 BC – The first of Cicero’s Philippics (oratorical attacks) on Mark Antony. He will make 14 of them over the next several months. 31 BC – Final War of the Roman Republic: Battle of Actium – off the western coast of Greece, forces of Octavian defeat troops under Mark Antony and Cleopatra.