Oops, it doesn't look like 'flip flop flip flop day' is a national day..

Other days

ponytail

Ponytail Day

tell a fairytale

Tell A Fairytale Day

gallery

Gallery Day

lumpy rug

Lumpy Rug Day

prosecco

Prosecco Day

pick me

Pick Me Day

one

One Day

Emoji Day

gum

Gum Day

lost sock memorial

Lost Sock Memorial Day