Oops, it doesn't look like 'high fivr day' is a national day..

Other days

cursing

Cursing Day
lisp

Lisp Day
bow tie

Bow Tie Day
my little pony

My Little Pony Day
special education

Special Education Day
martini

Martini Day
blanket fort

Blanket Fort Day
hoodie

Hoodie Day
lash

Lash Day
youth

Youth Day