Oops, it doesn't look like 'anthem before start of play on day' is a national day..

Other days

lisp

Lisp Day
offer

Offer Day
bounce

Bounce Day
law

Law Day
martini

Martini Day
boy friend

Boy Friend Day
camera

Camera Day
pampering

Pampering Day
blanket fort

Blanket Fort Day
kale

Kale Day