Oops, it doesn't look like 'confuse piff with a leprechaun day' is a national day..

Other days

china

China Day
boba

Boba Day
bow tie

Bow Tie Day
ride the wind

Ride The Wind Day
nae nae

Nae Nae Day
healing

Healing Day
lash

Lash Day
brow

Brow Day
reading

Reading Day
cat girl

Cat Girl Day