Oops, it doesn't look like 'museum of the united states army opens day' is a national day..

Other days

Eat What You Want Day

Fiancee Day

Polyamory Day

Ask Out Your Crush Day

Hoodie Day

Ponytail Day

Self Appreciation Day

African Immigrant And Refugee Hiv And Hep Awareness Day

Kiss A Ginger Day

Prescription Drug Take Back Day