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

Other days

stud

Stud Day
china

China Day
get funky

Get Funky Day
cursing

Cursing Day
believe

Believe Day
comfy

Comfy Day
ride the wind

Ride The Wind Day
self care

Self Care Day
pick me

Pick Me Day
eat what you want

Eat What You Want Day