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

Other days

youth

Youth Day
ponytail

Ponytail Day
hoodie

Hoodie Day
self appreciation

Self Appreciation Day
slime

Slime Day
promposal

Promposal Day
kale

Kale Day
lumpy rug

Lumpy Rug Day
bow tie

Bow Tie Day
polyamory

Polyamory Day