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

Other days

slime

Slime Day
bounce

Bounce Day
bow tie

Bow Tie Day
first love

First Love Day
pick me

Pick Me Day
pumpkin

Pumpkin Day
special education

Special Education Day
get funky

Get Funky Day
boba

Boba Day
kiss a ginger

Kiss A Ginger Day