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

Other days

singles

Singles Day
polyamory

Polyamory Day
artists

Artists Day
reading

Reading Day
boy friend

Boy Friend Day
blanket fort

Blanket Fort Day
ruby

Ruby Day
my little pony

My Little Pony Day
ponytail

Ponytail Day
tell ur crush you like them

Tell Ur Crush You Like Them Day