November is the eleventh and penultimate month of the year in the Julian and Gregorian Calendars, the fourth and last of four months to have a length of 30 days, and the fifth and last of five months to have a length of less than 31 days. November was the ninth month of the ancient Roman calendar. November retained its name (from the Latin novem meaning "nine") when January and February were added to the Roman calendar. November is a month of late spring in the Southern Hemisphere and late autumn in the Northern Hemisphere. Therefore, November in the Southern Hemisphere is the seasonal equivalent of May in the Northern Hemisphere and vice versa. In Ancient Rome, Ludi Plebeii was held from November 4–17, Epulum Jovis was held on November 13, and Brumalia celebrations began on November 24. These dates do not correspond to the modern Gregorian calendar.