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

Other days

azonto is acceptable

Azonto Is Acceptable Day
blanket fort

Blanket Fort Day
law

Law Day
brow

Brow Day
youth

Youth Day
hoodie

Hoodie Day
slime

Slime Day
lumpy rug

Lumpy Rug Day
unicorn

Unicorn Day
my little pony

My Little Pony Day