Oops, it doesn't look like 'rectum day' is a national day..

Other days

lisp

Lisp Day
camera

Camera Day
ride the wind

Ride The Wind Day
boy friend

Boy Friend Day
tulip

Tulip Day
bubble bath

Bubble Bath Day
hannah

Hannah Day
stud

Stud Day
eat what you want

Eat What You Want Day
boba

Boba Day