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

Other days

tell a fairytale

Tell A Fairytale Day
embarrass your best friend

Embarrass Your Best Friend Day
kale

Kale Day
fiancee

Fiancee Day
lash

Lash Day
offer

Offer Day
one

One Day
boy friend

Boy Friend Day
believe

Believe Day
bow tie

Bow Tie Day