Oops, it doesn't look like 'team alumni feature on mlb day' is a national day..

Other days

Chocolate Milkshake Day

Martini Day

Slime Day

Hot Chocolate Day

Tell A Fairytale Day

African Immigrant And Refugee Hiv And Hep Awareness Day

Brow Day

Nae Nae Day

First Love Day

Carpenters Day