November (Roman month) favored the cult of Isis. The Romans did not number days of a month sequentially from the first day through the last. Instead, they counted back from the three fixed points of the month: the Nones (5th or 7th), the Ides (13th or 15th), and the Kalends (1st) of the following month. The Nones of November was the 5th, and the Ides the 13th. The last day of November was the "pridie Kalendas Decembrīs," "day before the Kalends of December". Roman counting was inclusive; November 9 was "ante diem V Idūs Novembrīs", "the 5th day before the Ides of November,"
September (Roman month) holidays. Unless otherwise noted, the dating and observances on the following table are from H.H. Scullard, "Festivals and Ceremonies of the Roman Republic" (Cornell University Press, 1981), pp. 96–115. After the Ides, dates are given for the 30-day month of the Julian calendar; pre-Julian dates of festivals are noted parenthetically. September has a concentration of imperial birthdays "(dies natales)": Aurelian on the 9th, Trajan on the 18th, Antoninus Pius on the 19th, and Augustus on the 23rd. Inscriptions throughout the Empire record religious dedications made on these days, often by military personnel. The Genius of "Legio II Italica Pia", an