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

Other days

Emoji Day

law

Law Day

pumpkin

Pumpkin Day

believe

Believe Day

kiss a brunette

Kiss A Brunette Day

nae nae

Nae Nae Day

polyamory

Polyamory Day

camera

Camera Day

hoodie

Hoodie Day

chocolate milkshake

Chocolate Milkshake Day