Oops, it doesn't look like 'attention for a selfless act on her wedding day' is a national day..

Other days

Unicorn Day

Buddy Day

Tell Ur Crush You Like Them Day

Ride The Wind Day

Slime Day

African Immigrant And Refugee Hiv And Hep Awareness Day

Gum Day

Carpenters Day

Embarrass Your Best Friend Day

Cursing Day