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

Other days

lash

Lash Day
artists

Artists Day
prosecco

Prosecco Day
law

Law Day
eat what you want

Eat What You Want Day
one

One Day
brow

Brow Day
boyfriend

Boyfriend Day
pick me

Pick Me Day
fiancee

Fiancee Day