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

Other days

hoodie

Hoodie Day
brow

Brow Day
buddy

Buddy Day
gum

Gum Day
book

Book Day
hiv awareness

Hiv Awareness Day
lash

Lash Day
singles

Singles Day
ride the wind

Ride The Wind Day
stud

Stud Day