In around B.C. 713, January and February were added by Numa Pompilius and January 1st became New Year's Day, while this system was not used by governmental officers until B.C. 153 (the yearly calendar was revised to that starting from January and ending with December and the seventh to the twelfth months named in a language branched from Latin became names in Latin such as [in English as examples]: September [meaning the seventh], October [meaning the eighth], November [meaning the ninth], and December [meaning the tenth].)
紀元前713年頃、NumaPompiliusによりJanuaryとFebruaryが加えられ、1Januaryが正月（年の暦は、JanuaryからDecember、現代英語を含むラテン語派生系言語の7月から12月は、ラテン語：（例として英語では）September,7番目、October,8番目、November,9番目、December,10番目、の意味））になったが、執政官には紀元前153年まで使われなかった。