The Roman god who gives January its name is Janus. Roman tradition associated Janus with doorways, transitions, beginnings, and endings, making him a natural symbol for the turn of the year.
Janus is commonly depicted with two faces, one looking forward and one looking backward. This image represents the ability to consider the past while anticipating what comes next. The Latin name for January, Ianuarius, derives from Janus.
January did not always begin the Roman year. In the early Roman calendar, March was the first month, but January became the opening month after calendar reforms and changing administrative practice. The Julian calendar, introduced by Julius Caesar in 46 BCE, helped establish the calendar structure behind the later Gregorian system.
Janus was not simply a god of New Year’s celebrations. Romans also invoked him at doors, gates, journeys, agreements, and other moments of passage. His symbolism explains why his name remains linked to fresh starts.