Oops, it doesn't look like 'realize just how single and worthless you actually are day' is a national day..

Other days

Carpenters Day

Reading Day

African Immigrant And Refugee Hiv And Hep Awareness Day

Bounce Day

Stress Awareness Day

Ride The Wind Day

Lash Day

Tell Ur Crush You Like Them Day

Kiss A Ginger Day

Brow Day