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

Other days

hoodie

Hoodie Day
stress awareness

Stress Awareness Day
kale

Kale Day
bonang

Bonang Day
tell a fairytale

Tell A Fairytale Day
aloxolt

Aloxolt Day
polyamory

Polyamory Day
ruby

Ruby Day
ponytail

Ponytail Day
bow tie

Bow Tie Day