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

Other days

ponytail

Ponytail Day
nae nae

Nae Nae Day
blanket fort

Blanket Fort Day
bounce

Bounce Day
law

Law Day
frozen yogurt

Frozen Yogurt Day
chocolate milkshake

Chocolate Milkshake Day
cuddle up

Cuddle Up Day
reading

Reading Day
youth

Youth Day