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

Other days

one

One Day

girl friend

Girl Friend Day

hoodie

Hoodie Day

unicorn

Unicorn Day

my little pony

My Little Pony Day

donate your hair

Donate Your Hair Day

cursing

Cursing Day

hannah

Hannah Day

brow

Brow Day

artists

Artists Day