Oops, it doesn't look like 'your an ass hole day' is a national day..

Other days

tulip

Tulip Day
pumpkin

Pumpkin Day
promposal

Promposal Day
donate your hair

Donate Your Hair Day
one

One Day
kale

Kale Day
lash

Lash Day
ride the wind

Ride The Wind Day
hot chocolate

Hot Chocolate Day
offer

Offer Day