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

Other days

cuddle up

Cuddle Up Day
self care

Self Care Day
china

China Day
stud

Stud Day
believe

Believe Day
eat what you want

Eat What You Want Day
ask out your crush

Ask Out Your Crush Day
lisp

Lisp Day
lash

Lash Day
girl friend

Girl Friend Day