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

Other days

bounce

Bounce Day
bow tie

Bow Tie Day
lisp

Lisp Day
boba

Boba Day
girl friend

Girl Friend Day
unicorn

Unicorn Day
buddy

Buddy Day
my little pony

My Little Pony Day
self care

Self Care Day
book

Book Day