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

Other days

african immigrant and refugee hiv and hep awareness

African Immigrant And Refugee Hiv And Hep Awareness Day
boy friend

Boy Friend Day
cursing

Cursing Day
hiv awareness

Hiv Awareness Day
self appreciation

Self Appreciation Day
me

Me Day
kale

Kale Day
azonto is acceptable

Azonto Is Acceptable Day
martini

Martini Day
mean girls

Mean Girls Day