A two-headed deity
We can thank a god for January.
According to the Online Eytmology Dictionary, the word came into English in the late 13th century and was spelled “Ieneur, from Old North French Genever.” (In modern French, the name is close to English — janvier. Unlike its English counterpart, it‘s not capitalized unless it begins a sentence.)
The dictionary also notes that the word eventually came into French “from Latin Ianuarius (mensis) ‘(the month) of Janus.’” Janus was a Roman god with two faces, one looking backward and one looking forward. He was associated with time because he could look into the past and into the future.
Head of Janus, Vatican Museum in Rome
Photo by Loudon dodd courtesy of Wikipedia