Which ancient Roman festival honoring Janus influenced New Year's celebrations in January?

The Kalends of January was the ancient Roman festival honoring Janus that influenced New Year's celebrations in January.

The Roman kalends was the first day of each month, and the Kalends of January marked the beginning of the Roman civil year. Janus, the god associated with doorways, transitions, and beginnings, gave January its name. Romans offered good wishes, exchanged gifts, and treated the day as a time for favorable beginnings.

The celebration was not identical to the modern New Year’s Eve countdown. Roman religious life followed a different calendar and included many festivals, while the official start of the year changed historically. January 1 became especially important after calendar reforms and the consolidation of Roman administrative practice.

The name “kalends” also produced the English word “calendar.” Saturnalia, by contrast, was a separate December festival dedicated to Saturn. It was famous for feasting and role reversals but was not the Roman New Year festival named here.