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

Other days

bounce

Bounce Day
frozen yogurt

Frozen Yogurt Day
boba

Boba Day
law

Law Day
nail polish

Nail Polish Day
aloxolt

Aloxolt Day
eat what you want

Eat What You Want Day
hannah

Hannah Day
bonang

Bonang Day
azonto is acceptable

Azonto Is Acceptable Day