December 21 December 22, unless that date is a Sunday, in which case it's moved to the 23rd: December 22 "'Last Saturday before Christmas: December 22" Sunday before Christmas: December 23 December 26, unless that day is a Sunday, in which case the 27th: December 26 Last Friday before Christmas: December 28 Sunday after Christmas: December 30 December December is the twelfth and final month of the year in the Julian and Gregorian Calendars and is the seventh and last of seven months to have a length of 31 days. December got its name from the Latin word "decem" (meaning ten)
December (Roman month) 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 December was the 5th, and the Ides the 13th. The last day of December was the "pridie Kalendas Ianuarias," "day before the Januarian Kalends". Roman counting was inclusive; December 9 was "ante diem V Idūs Decembrīs", "the 5th day before the Ides of December," usually abbreviated "a.d. V Id. Dec." (or with the "a.d." omitted altogether); December 24 was "IX Kal. Ian.", "the 9th day before the Kalends of Ianuarius," on the Julian calendar