monthlexia 

Getting your months mixed up.

"I'll be visiting in August... I mean, November."

"Suffering from monthlexia again?!"

monthlexia by LimelightCopy September 17, 2014

mathlexia 

The inability to do math in your head.

Brian's mathlexia made blackjack a challenge; it always took him forever to correctly add up the cards.

mathlexia by Midnight Noon September 8, 2013

Monthsexual 

A sexuality where you love a month and become attracted to it.

"Dude, I'm Monthsexual."

Monthsexual by anonomomo December 19, 2022