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

Other days

first love

First Love Day
bounce

Bounce Day
eat what you want

Eat What You Want Day
brow

Brow Day
believe

Believe Day
lash

Lash Day
ormille

Ormille Day
ride the wind

Ride The Wind Day
bonang

Bonang Day
unicorn

Unicorn Day