Oops, it doesn't look like 'leave me on seen day' is a national day..

Other days

kale

Kale Day
stress awareness

Stress Awareness Day
coffee

Coffee Day
fiancee

Fiancee Day
hoodie

Hoodie Day
slime

Slime Day
my little pony

My Little Pony Day
lash

Lash Day
ruby

Ruby Day
boy friend

Boy Friend Day