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

Other days

slime

Slime Day
bow tie

Bow Tie Day
one

One Day
hot chocolate

Hot Chocolate Day
buddy

Buddy Day
lash

Lash Day
kiss a brunette

Kiss A Brunette Day
self care

Self Care Day
stud

Stud Day
lisp

Lisp Day