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

Other days

youth

Youth Day
ride the wind

Ride The Wind Day
nae nae

Nae Nae Day
kiss a brunette

Kiss A Brunette Day
buddy

Buddy Day
artists

Artists Day
boy friend

Boy Friend Day
comfy

Comfy Day
kale

Kale Day
special education

Special Education Day