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

Other days

carpenters

Carpenters Day
ride the wind

Ride The Wind Day
blanket fort

Blanket Fort Day
prosecco

Prosecco Day
one

One Day
lisp

Lisp Day
get funky

Get Funky Day
polyamory

Polyamory Day
singles

Singles Day
ruby

Ruby Day