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

Other days

prescription drug take back

Prescription Drug Take Back Day
tell ur crush you like them

Tell Ur Crush You Like Them Day
slime

Slime Day
kiss a ginger

Kiss A Ginger Day
me

Me Day
unicorn

Unicorn Day
self appreciation

Self Appreciation Day
boy friend

Boy Friend Day
my little pony

My Little Pony Day
ruby

Ruby Day