It'll be a long day in January
describing something that will never happen
e.g. It'll be a long day in January when you beat me at basketball.
Mad as a March hare
acting crazy (hares act crazy during their March breeding sesons)
e.g. I like John but he acts as mad as March hare.
April showers bring May flowers
rain in April = flowers growing
e.g. You hate this rainy weather but remember April showers bring May flowers.
when one person in a relationship is a lot older than the other
e.g. People are always skeptical of May-December.
Maybees don't fly in June
when telling someone to stop changing their mind so much
e.g. I wish you would make decision. Maybees don't fly in June!
A cold day in July
use it to describe a situation or event that will never happen
e.g. It'll be a cold day in July when you beat me at basketball.