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

Other days

coffee

Coffee Day
promposal

Promposal Day
nae nae

Nae Nae Day
lumpy rug

Lumpy Rug Day
comfy

Comfy Day
brow

Brow Day
girl friend

Girl Friend Day
cat girl

Cat Girl Day
lisp

Lisp Day
boba

Boba Day