Oops, it doesn't look like 'Flip Flop Martini day' is a national day..

Other days

camera

Camera Day
bubble bath

Bubble Bath Day
pampering

Pampering Day
unicorn

Unicorn Day
girl friend

Girl Friend Day
youth

Youth Day
bow tie

Bow Tie Day
slime

Slime Day
mean girls

Mean Girls Day
lisp

Lisp Day