Oops, it doesn't look like 'piss ur bf off day' is a national day..

Other days

cuddle up

Cuddle Up Day
one

One Day
slime

Slime Day
stud

Stud Day
boy friend

Boy Friend Day
nae nae

Nae Nae Day
kiss a brunette

Kiss A Brunette Day
lisp

Lisp Day
unicorn

Unicorn Day
donate your hair

Donate Your Hair Day