Oops, it doesn't look like 'rancor for at least a day' is a national day..

Other days

Frozen Yogurt Day

Kiss A Brunette Day

Raise Awerness Of Zeus Day

Believe Day

Pick Me Day

Lost Sock Memorial Day

Tell A Fairytale Day

Stud Day

Cuddle Up Day

African Immigrant And Refugee Hiv And Hep Awareness Day