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

Other days

lash

Lash Day
stud

Stud Day
cursing

Cursing Day
promposal

Promposal Day
stress awareness

Stress Awareness Day
bow tie

Bow Tie Day
boyfriend

Boyfriend Day
polyamory

Polyamory Day
boy friend

Boy Friend Day
tulip

Tulip Day