A month is a portion of a year corresponding roughly to the passage of the earth round the moon (a 'lunar month', of which there are, in fact, thirteen). There are twelve terrestrial months. They are named after pagan gods and goddesses (January, February, March, April, May, June, August), Roman emperors (July, August) and numbers (September-December incl.). The number of days varies, but a handy way to remember which is which is:
Thirty days hath September April, June, and November All the rest have thirty-one Except for February alone Which has twenty-eight days clear And twenty-nine in each leap year.