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

Other days

tulip

Tulip Day
brow

Brow Day
carpenters

Carpenters Day
blanket fort

Blanket Fort Day
azonto is acceptable

Azonto Is Acceptable Day
china

China Day
african immigrant and refugee hiv and hep awareness

African Immigrant And Refugee Hiv And Hep Awareness Day
stud

Stud Day
stress awareness

Stress Awareness Day
ruby

Ruby Day