January was established as the first
the first month of the year by the Roman Calendar. It was named after
the god Janus

(Latin word for door). Janus has two faces which allowed
him to look both backwards into the old year and forwards into the new
one at the same time. He was the 'spirit of the opening'.

In
the very earliest Roman calendars there were no months of January or
February at all. The ancient Roman calendar had only ten months and the
new year started the year on 1 March. To the Romans, ten was a very
important number. Even when January (or Januarius as the Romans called
it) was added, the New Year continued to start in March. It remained so
in England and her colonies until about 200 years ago.

The 13th of January has gained the reputation for being the coldest day of the year.