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

Other days

cuddle up

Cuddle Up Day
youth

Youth Day
carpenters

Carpenters Day
bow tie

Bow Tie Day
comfy

Comfy Day
one

One Day
reading

Reading Day
polyamory

Polyamory Day
kiss a brunette

Kiss A Brunette Day
eat what you want

Eat What You Want Day