Oops, it doesn't look like 'flag upside down on day' is a national day..

Other days

youth

Youth Day
get funky

Get Funky Day
camera

Camera Day
kiss a ginger

Kiss A Ginger Day
buddy

Buddy Day
bounce

Bounce Day
cursing

Cursing Day
stud

Stud Day
fiancee

Fiancee Day
cuddle up

Cuddle Up Day