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

Other days

cursing

Cursing Day

african immigrant and refugee hiv and hep awareness

African Immigrant And Refugee Hiv And Hep Awareness Day

law

Law Day

offer

Offer Day

promposal

Promposal Day

comfy

Comfy Day

Me Day

hiv awareness

Hiv Awareness Day

ponytail

Ponytail Day

my little pony

My Little Pony Day