Oops, it doesn't look like 'smack her ass day' is a national day..

Other days

singles

Singles Day
buddy

Buddy Day
camera

Camera Day
nae nae

Nae Nae Day
healing

Healing Day
kiss a brunette

Kiss A Brunette Day
self care

Self Care Day
boy friend

Boy Friend Day
cuddle up

Cuddle Up Day
ruby

Ruby Day