Oops, it doesn't look like 'park that day' is a national day..

Other days

self appreciation

Self Appreciation Day
lisp

Lisp Day
china

China Day
lash

Lash Day
reading

Reading Day
hiv awareness

Hiv Awareness Day
unicorn

Unicorn Day
nae nae

Nae Nae Day
lumpy rug

Lumpy Rug Day
ride the wind

Ride The Wind Day