October (Roman month) did not number days of a month sequentially from the 1st through the last day. 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 October was the 7th, and the Ides was the 15th. The last day of October was the "pridie Kalendas Novembris," "day before the Kalends of November". Roman counting was inclusive; October 9 was "ante diem VII Idūs Octobris", "the 7th day before the Ides of October," usually abbreviated "a.d. VII Id. Oct."
Iunius (month) dating and observances on the following table are from H.H. Scullard, "Festivals and Ceremonies of the Roman Republic". Scullard places the Taurian Games on June 25–26 on a five-year cycle, but other scholars believe these "ludi" had no regular date and were held as a crisis ritual when needed. After the Ides, dual dates are given to represent both the earlier calendar, when June had 29 days and July was called "Quinctilis", and the 30-day month of the Julian calendar. Iunius (month) On the ancient Roman calendar, mensis Iunius or Iunius, also Junius (June), was the fourth month, following "Maius"