Oops, it doesn't look like 'not give a fuck day' is a national day..

Other days

ponytail

Ponytail Day
stud

Stud Day
believe

Believe Day
book

Book Day
pumpkin

Pumpkin Day
lash

Lash Day
my little pony

My Little Pony Day
coffee

Coffee Day
tulip

Tulip Day
gum

Gum Day