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

Other days

kale

Kale Day
cuddle up

Cuddle Up Day
latina equal pay

Latina Equal Pay Day
get funky

Get Funky Day
believe

Believe Day
stud

Stud Day
fiancee

Fiancee Day
buddy

Buddy Day
hannah

Hannah Day
ruby

Ruby Day