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

Other days

law

Law Day
unicorn

Unicorn Day
gallery

Gallery Day
healing

Healing Day
my little pony

My Little Pony Day
self care

Self Care Day
cuddle up

Cuddle Up Day
coffee

Coffee Day
nail polish

Nail Polish Day
eat what you want

Eat What You Want Day