Oops, it doesn't look like 'park on public lands day' is a national day..

Other days

gum

Gum Day
emoji

Emoji Day
african immigrant and refugee hiv and hep awareness

African Immigrant And Refugee Hiv And Hep Awareness Day
chocolate milkshake

Chocolate Milkshake Day
carpenters

Carpenters Day
tulip

Tulip Day
hiv awareness

Hiv Awareness Day
blanket fort

Blanket Fort Day
cuddle up

Cuddle Up Day
stress awareness

Stress Awareness Day