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

Other days

believe

Believe Day

slime

Slime Day

stud

Stud Day

eat what you want

Eat What You Want Day

youth

Youth Day

cat girl

Cat Girl Day

get funky

Get Funky Day

gallery

Gallery Day

donate your hair

Donate Your Hair Day

lisp

Lisp Day