 Although March was originally the first month in the old Roman calendar, January became the first month of the calendar year either under Numa or under the Decemvirs about 450 BC (Roman writers differ).In contrast, each specific calendar year was identified by the names of the two consuls, who entered office on May 1 or March 15 until 153 BC, from when they entered office on January 1.Various Christian feast dates were used for the New Year in Europe during the Middle Ages, including March 25 (Feast of the Annunciation) and December 25.