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

Other days

brow

Brow Day
hoodie

Hoodie Day
slime

Slime Day
buddy

Buddy Day
tulip

Tulip Day
eat what you want

Eat What You Want Day
bonang

Bonang Day
tell a fairytale

Tell A Fairytale Day
kale

Kale Day
ride the wind

Ride The Wind Day