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

Other days

self care

Self Care Day
singles

Singles Day
ask out your crush

Ask Out Your Crush Day
my little pony

My Little Pony Day
slime

Slime Day
bow tie

Bow Tie Day
unicorn

Unicorn Day
book

Book Day
cursing

Cursing Day
bounce

Bounce Day