Welcome, dear reader, to January. January is a time to look back upon the dunghill of a year that has passed, and to look forward to the miseries to come. However, it is impossible to look both backwards and forwards unless you have two faces and you only have one, I hope. Otherwise you suffer from the horrid genetic disorder known as diprosopus, or you are the Roman god Janus [see picture].
Because Janus had two faces and was able to look in two directions he was the god of boundaries. The first month of the year, being the boundary between the old and the new, was therefore sacred to him and was named Januarius or January.
Janus was also, of course, the god of gates and passages and doorways and portals of all sorts, and that is why doorkeepers are called janitors.
Leonato: You will never run mad, niece.
Beatrice: No, not till a hot January.
I am told that these lines from Much Ado About Nothing sound rather odd when performed in Australia.
Sacred to Janus