Oops, it doesn't look like 'hero to this day' is a national day..

Other days

tulip

Tulip Day
ride the wind

Ride The Wind Day
eat what you want

Eat What You Want Day
youth

Youth Day
gum

Gum Day
nae nae

Nae Nae Day
brow

Brow Day
nail polish

Nail Polish Day
cuddle up

Cuddle Up Day
book

Book Day