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

Other days

bow tie

Bow Tie Day
singles

Singles Day
healing

Healing Day
ruby

Ruby Day
ride the wind

Ride The Wind Day
stud

Stud Day
lisp

Lisp Day
ask out your crush

Ask Out Your Crush Day
special education

Special Education Day
martini

Martini Day