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

Other days

lisp

Lisp Day
ride the wind

Ride The Wind Day
girl friend

Girl Friend Day
slime

Slime Day
ponytail

Ponytail Day
coffee

Coffee Day
bounce

Bounce Day
boy friend

Boy Friend Day
prosecco

Prosecco Day
ormille

Ormille Day