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

Other days

gallery

Gallery Day
cuddle up

Cuddle Up Day
polyamory

Polyamory Day
carpenters

Carpenters Day
my little pony

My Little Pony Day
tell a fairytale

Tell A Fairytale Day
ruby

Ruby Day
gum

Gum Day
one

One Day
boba

Boba Day