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

Other days

aloxolt

Aloxolt Day
girl friend

Girl Friend Day
lumpy rug

Lumpy Rug Day
unicorn

Unicorn Day
bow tie

Bow Tie Day
camera

Camera Day
ruby

Ruby Day
polyamory

Polyamory Day
kiss a ginger

Kiss A Ginger Day
bubble bath

Bubble Bath Day