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

Other days

bounce

Bounce Day
donate your hair

Donate Your Hair Day
youth

Youth Day
nae nae

Nae Nae Day
cat girl

Cat Girl Day
kiss a ginger

Kiss A Ginger Day
hoodie

Hoodie Day
lisp

Lisp Day
unicorn

Unicorn Day
mean girls

Mean Girls Day