Janus

Roman deity
In ancient Roman religion and myth, Janus is the god of beginnings, gates, transitions, time, duality, doorways, passages, frames, and endings. He is usually depicted as having two faces. The month of January is named for Janus. According to ancient Roman farmers’ almanacs, Juno was mistaken as the tutelary deity of the month of January, but Juno is the tutelary deity of the month of June. Wikipedia

Other names Ianuspater (“Janus Father”), Ianus Quadrifrons (“Janus Fourfaced”), Ianus Bifrons (“Two-faced Janus”)
Abode at the limits of Earth, at the extremity of Heaven
Symbol two faces

Click on individual items for more information & uses.