I had memorized this poem as a girl, to help me with the days of each month. As I learned it, I would get stuck around February and then the rhyme of the poem sort of fell apart:
Thirty days hath September,
April, June, and November
All the rest have thirty-one,
Except for February; it alone has twenty-eight,
and in a leap year it has twenty-nine.
It was fun to find this article, with some better endings!
Except for February alone...
Which hath twenty-eight days clear,
And twenty-nine in each leap year,
Which has eight and a score
Until leap year gives it one day more,
Which hath but twenty-eight, in fine,
Till leap year make it twenty-nine.