November (Roman month) November (Roman month) November (from Latin "novem", "nine") or mensis November was originally the ninth of ten months on the Roman calendar, following October ("octo", "eight") and preceding December ("decem", "ten"). It had 29 days. In the reform that resulted in a 12-month year, November became the eleventh month, but retained its name, as did the other months from September through December. A day was added to November during the Julian calendar reform in the mid-40s BC. The outstanding event during November was the Plebeian Games from the 4th through the 17th. The month had few other festivals. It was
Gregorian calendar It also specifies its epact relative to 1 January, in contrast with the Julian calendar, which specified it relative to 22 March. The old date was derived from the Greek system: the earlier "Supputatio Romana" specified it relative to 1 January. During the period between 1582, when the first countries adopted the Gregorian calendar, and 1923, when the last European country adopted it, it was often necessary to indicate the date of some event in both the Julian calendar and in the Gregorian calendar, for example, "10/21 February 1750/51", where the dual year accounts for some countries already beginning their