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

Other days

coffee

Coffee Day
offer

Offer Day
bounce

Bounce Day
eat what you want

Eat What You Want Day
ponytail

Ponytail Day
cat girl

Cat Girl Day
brow

Brow Day
boyfriend

Boyfriend Day
lash

Lash Day
kiss a ginger

Kiss A Ginger Day