Oops, it doesn't look like 'interest else that day' is a national day..

Other days

cuddle up

Cuddle Up Day
brow

Brow Day
hot chocolate

Hot Chocolate Day
stud

Stud Day
lisp

Lisp Day
ormille

Ormille Day
gum

Gum Day
martini

Martini Day
boy friend

Boy Friend Day
first love

First Love Day