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

Other days

ruby

Ruby Day
blanket fort

Blanket Fort Day
stress awareness

Stress Awareness Day
martini

Martini Day
nae nae

Nae Nae Day
aloxolt

Aloxolt Day
bow tie

Bow Tie Day
latina equal pay

Latina Equal Pay Day
cursing

Cursing Day
coffee

Coffee Day