Januarius: from Junus, the god of the doorway with two faces, one looking back at the old year and one forward to the new.
Februarius: a festival of purification.
Martius: from Mars, the God of war.
Aprilis: from apirere, to open.
Maius: from the goddess Maia.
Junonius: from the goddess Juno.
Julius: named after Julius Caesar.
Augustus: named after Augustus Caesar.
The addition of July and August affected the remaining months, which had been named from their position in the calendar.
September: the seventh month.
October: the eighth month.
November: the ninth month.
December: the tenth month.