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

Other days

promposal

Promposal Day
my little pony

My Little Pony Day
ruby

Ruby Day
ride the wind

Ride The Wind Day
bonang

Bonang Day
lumpy rug

Lumpy Rug Day
emoji

Emoji Day
cat girl

Cat Girl Day
one

One Day
boy friend

Boy Friend Day