The Roman god Janus gives January its name and is associated with beginnings and transitions.
Janus was traditionally depicted with two faces, one looking forward and the other backward. This imagery made him a natural symbol for a month that looks back at the year just ended while facing the year ahead.
The Latin name for January, Ianuarius, derives from Janus. The Roman calendar year originally began in March, but January 1 became the start of the consular year in 153 BCE, helping establish the date's importance in Roman public life.
Janus was not simply a god of the new year. Romans also connected him with doorways, gates, passages, and change. His name is reflected in English words such as “January” and “January's” calendar symbolism, while the month itself became the opening point of the Gregorian calendar used in much of the modern world.