Oops, it doesn't look like 'shut tf up day' is a national day..

Other days

ruby

Ruby Day
nail polish

Nail Polish Day
lisp

Lisp Day
me

Me Day
hiv awareness

Hiv Awareness Day
eat what you want

Eat What You Want Day
self appreciation

Self Appreciation Day
ride the wind

Ride The Wind Day
my little pony

My Little Pony Day
singles

Singles Day