Oops, it doesn't look like 'informal drunken highschool reunion day' is a national day..

Other days

Believe Day

Ponytail Day

Mean Girls Day

Nae Nae Day

Azonto Is Acceptable Day

Donate Your Hair Day

Chocolate Milkshake Day

Special Education Day

Aloxolt Day

African Immigrant And Refugee Hiv And Hep Awareness Day