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

Other days

fiancee

Fiancee Day
comfy

Comfy Day
promposal

Promposal Day
boy friend

Boy Friend Day
hannah

Hannah Day
hiv awareness

Hiv Awareness Day
girl friend

Girl Friend Day
pumpkin

Pumpkin Day
self appreciation

Self Appreciation Day
law

Law Day