Janus gave January its name and was honored at New Year in ancient Rome.
Janus was the Roman god of beginnings, transitions, doorways, passages, and endings. Romans commonly depicted him with two faces: one looking forward and one looking backward. That imagery made him especially appropriate for the transition from one year to the next.
The month of January derives from the Latin name Ianuarius, meaning the month of Janus. Roman religious observances called Agonalia took place in January, and January 1 became an important date for public offices and civic ceremonies. The Roman calendar’s treatment of the year changed over time, so modern New Year customs are not a direct copy of one ancient festival.
Janus is sometimes confused with Janus-faced imagery as a general symbol of hypocrisy. In Roman religion, however, the two faces primarily expressed the god’s connection with looking in two directions across a transition.