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

Other days

china

China Day
stress awareness

Stress Awareness Day
cursing

Cursing Day
nae nae

Nae Nae Day
bow tie

Bow Tie Day
fiancee

Fiancee Day
boba

Boba Day
hoodie

Hoodie Day
frozen yogurt

Frozen Yogurt Day
blanket fort

Blanket Fort Day