Oops, it doesn't look like 'landmarks his last day' is a national day..

Other days

one

One Day
reading

Reading Day
pumpkin

Pumpkin Day
bow tie

Bow Tie Day
fiancee

Fiancee Day
polyamory

Polyamory Day
gum

Gum Day
stud

Stud Day
ruby

Ruby Day
tulip

Tulip Day