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

Other days

blanket fort

Blanket Fort Day
camera

Camera Day
first love

First Love Day
hannah

Hannah Day
lash

Lash Day
cat girl

Cat Girl Day
my little pony

My Little Pony Day
bow tie

Bow Tie Day
tulip

Tulip Day
lost sock memorial

Lost Sock Memorial Day