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

Other days

polyamory

Polyamory Day
my little pony

My Little Pony Day
buddy

Buddy Day
bounce

Bounce Day
ormille

Ormille Day
hot chocolate

Hot Chocolate Day
boy friend

Boy Friend Day
lisp

Lisp Day
cat girl

Cat Girl Day
self care

Self Care Day