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

Other days

bow tie

Bow Tie Day
boy friend

Boy Friend Day
comfy

Comfy Day
martini

Martini Day
offer

Offer Day
stud

Stud Day
nae nae

Nae Nae Day
cat girl

Cat Girl Day
get funky

Get Funky Day
law

Law Day