 January (in Latin, "Ianuarius") is named after Janus, the god of beginnings and transitions in Roman mythology.Traditionally, the original Roman calendar consisted of 10 months totaling 304 days, winter being considered a month-less period.Around 713 BC, the semi-mythical successor of Romulus, King Numa Pompilius, is supposed to have added the months of January and February, so that the calendar covered a standard lunar year (354 days).