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

Other days

believe

Believe Day
buddy

Buddy Day
camera

Camera Day
kale

Kale Day
lost sock memorial

Lost Sock Memorial Day
nail polish

Nail Polish Day
lash

Lash Day
cursing

Cursing Day
donate your hair

Donate Your Hair Day
slime

Slime Day