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

Other days

singles

Singles Day
slime

Slime Day
martini

Martini Day
artists

Artists Day
eat what you want

Eat What You Want Day
pampering

Pampering Day
bow tie

Bow Tie Day
boyfriend

Boyfriend Day
hannah

Hannah Day
lisp

Lisp Day