Oops, it doesn't look like 'opera take over the school for the day' is a national day..

Other days

Lumpy Rug Day

Brow Day

Carpenters Day

Lost Sock Memorial Day

Unicorn Day

Appreciate Yaself A Lil Extra Day

Cat Girl Day

Kiss A Brunette Day

African Immigrant And Refugee Hiv And Hep Awareness Day

Hiv Awareness Day