Oops, it doesn't look like 'girlfriend or boyfriend day' is a national day..

Other days

cursing

Cursing Day
gum

Gum Day
buddy

Buddy Day
lash

Lash Day
blanket fort

Blanket Fort Day
comfy

Comfy Day
polyamory

Polyamory Day
carpenters

Carpenters Day
frozen yogurt

Frozen Yogurt Day
ruby

Ruby Day