Oops, it doesn't look like 'goofing off day' is a national day..

Other days

nae nae

Nae Nae Day
kale

Kale Day
lost sock memorial

Lost Sock Memorial Day
hot chocolate

Hot Chocolate Day
cuddle up

Cuddle Up Day
china

China Day
offer

Offer Day
bow tie

Bow Tie Day
lash

Lash Day
boy friend

Boy Friend Day