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

Other days

comfy

Comfy Day
boba

Boba Day
tell a fairytale

Tell A Fairytale Day
get funky

Get Funky Day
nae nae

Nae Nae Day
blanket fort

Blanket Fort Day
girl friend

Girl Friend Day
bow tie

Bow Tie Day
law

Law Day
ormille

Ormille Day