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

Other days

gum

Gum Day
bonang

Bonang Day
boy friend

Boy Friend Day
me

Me Day
gallery

Gallery Day
hoodie

Hoodie Day
nae nae

Nae Nae Day
one

One Day
kiss a ginger

Kiss A Ginger Day
unicorn

Unicorn Day