Oops, it doesn't look like 'blue flu day' is a national day..

Other days

boba

Boba Day
my little pony

My Little Pony Day
bubble bath

Bubble Bath Day
unicorn

Unicorn Day
gum

Gum Day
kiss a brunette

Kiss A Brunette Day
one

One Day
mean girls

Mean Girls Day
martini

Martini Day
nail polish

Nail Polish Day