The first month of the year, the beginning, was dedicated to Janus - one of the oldest gods of the Romans - and called January. His festival was celebrated in January 1st.
"Janus was the god of all beginnings and of passages such as doors, gates and bridges, often depicted with two faces, and was then called Janus Bifrons. There were several temples to Janus in Rome, the most famous was the one in the Forum Romanum, whose gates would be open in time of war, and only closed in times of peace.
"Janus was the patron of concrete and abstract beginnings of the world (such as the religion and the gods themselves), the human life, new historical ages, and economical enterprises. He was also the god of the home entrance ('ianua'), gates, bridges and covered and arcaded passages ('iani') named after him. He was frequently used to symbolize change and transitions such as the progression of past to future, of one condition to another, of one vision to another, the growing up of young people, and of one universe to another.
"He was also known as the figure representing time because he could see into the past with one face and into the future with the other. Hence, Janus was worshipped at the beginnings of the harvest and planting times, as well as marriages, deaths and other beginnings. He was representative of the middle ground between barbarity and civilization, rural country and urban cities, and youth and adulthood."