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

Other days

boba

Boba Day
blanket fort

Blanket Fort Day
nae nae

Nae Nae Day
camera

Camera Day
believe

Believe Day
comfy

Comfy Day
brow

Brow Day
boy friend

Boy Friend Day
cuddle up

Cuddle Up Day
artists

Artists Day