Janus, the Roman god shown with two faces, gave January its name and links it to new beginnings.
One face of Janus traditionally looks toward the past while the other looks toward the future. That imagery made him especially suitable for the boundary between one year and the next, when people review what has ended and anticipate what is beginning.
The Latin month name Ianuarius developed from Janus’s name. In the Roman calendar, January became the first month, although the precise history of the calendar’s beginning-of-year arrangements changed over time. The Julian calendar reforms helped establish January 1 as a significant civic date.
Janus was associated with doors, gates, passages, and transitions rather than with the modern idea of a party. This is why references to the god often appear in explanations of New Year symbolism. The month’s name is the lasting linguistic connection.