The tradition of New Year’s resolutions goes all the way back to 153 B.C. when Janus, a mythical king of early Rome, was placed at the head of the calendar.
Having two faces, Janus could look back on past events and forward to the future. Janus became the ancient symbol for resolutions, and many Romans looked for forgiveness from their enemies and also exchanged gifts before the beginning of each year.
The New Year has not always begun on January 1, and it doesn’t begin on that date for everywhere today. It begins on that date only for cultures that use a 365-day solar calendar. January 1 became the beginning of the New Year in 46 B.C., when Julius Caesar developed a calendar that would more accurately reflect the seasons than previous calendars had.
The Romans named the first month of the Year after Janus, the god of beginnings and the guardian of doors and entrances. He was always depicted with two faces, one on the front of his head and one on the back. At midnight on December 31, the Romans imagined Janus looking back at the old year and forward to the new.