My wife makes a fist and counts her knuckles and divots on her left hand: pinky Jan 31 divot Feb (28/29) ring March 31 divot April 30 middle May 31 divot

My wife makes a fist and counts her knuckles and divots on her left hand: pinky Jan 31 divot Feb (28/29) ring March 31 divot April 30 middle May 31 divot June 30 pointer July 31 (now head back the other way) pointer August 31 divot September 30 middle October 31 divot November 30 ring December 31 I don't know where she learned it, but it's genius.