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

Other days

cursing

Cursing Day
tulip

Tulip Day
mean girls

Mean Girls Day
azonto is acceptable

Azonto Is Acceptable Day
blanket fort

Blanket Fort Day
camera

Camera Day
slime

Slime Day
unicorn

Unicorn Day
singles

Singles Day
artists

Artists Day