Oops, it doesn't look like 'i scream in pain day' is a national day..

Other days

cat girl

Cat Girl Day
my little pony

My Little Pony Day
self appreciation

Self Appreciation Day
one

One Day
boba

Boba Day
slime

Slime Day
hannah

Hannah Day
blanket fort

Blanket Fort Day
artists

Artists Day
law

Law Day