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

Other days

boba

Boba Day
law

Law Day
carpenters

Carpenters Day
boyfriend

Boyfriend Day
self care

Self Care Day
my little pony

My Little Pony Day
mean girls

Mean Girls Day
ride the wind

Ride The Wind Day
latina equal pay

Latina Equal Pay Day
brow

Brow Day