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

Other days

brow

Brow Day
healing

Healing Day
boba

Boba Day
believe

Believe Day
eat what you want

Eat What You Want Day
unicorn

Unicorn Day
bow tie

Bow Tie Day
kale

Kale Day
pampering

Pampering Day
tell ur crush you like them

Tell Ur Crush You Like Them Day