Happy Bissextile Day

Our calendars which number the days of the month sequentially from the first day of the month result in a 29th day added to the end of February in the "leap" year, however this is not strictly correct. The "leap" day is in fact, added before the 24th. The 24th day of February is in roman usage ante diem sextum calendas martii (A.D. VI KAL. MAR.), the sixth day before the Kalends of March, every fourth year the calendar adds a second February 24, or bis, meaning twice, sextum, meaning sixth, day before March. For more about the Julian/Gregorian calendar click here.