Oops, it doesn't look like 'parks is free this day' is a national day..

Other days

nail polish

Nail Polish Day
boyfriend

Boyfriend Day
bow tie

Bow Tie Day
gum

Gum Day
lumpy rug

Lumpy Rug Day
bounce

Bounce Day
nae nae

Nae Nae Day
get funky

Get Funky Day
lisp

Lisp Day
ruby

Ruby Day