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

Other days

african immigrant and refugee hiv and hep awareness

African Immigrant And Refugee Hiv And Hep Awareness Day
self care

Self Care Day
hiv awareness

Hiv Awareness Day
lisp

Lisp Day
slime

Slime Day
ponytail

Ponytail Day
singles

Singles Day
believe

Believe Day
tell a fairytale

Tell A Fairytale Day
ask out your crush

Ask Out Your Crush Day