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

Other days

ruby

Ruby Day
unicorn

Unicorn Day
one

One Day
bounce

Bounce Day
embarrass your best friend

Embarrass Your Best Friend Day
self care

Self Care Day
buddy

Buddy Day
tulip

Tulip Day
hoodie

Hoodie Day
offer

Offer Day