Oops, it doesn't look like 'i took a photo in yosemite once day' is a national day..

Other days

Bubble Bath Day

Prescription Drug Take Back Day

Tell Ur Crush You Like Them Day

Bow Tie Day

Martini Day

Comfy Day

Lumpy Rug Day

Pick Me Day

African Immigrant And Refugee Hiv And Hep Awareness Day

Gum Day