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

Other days

ruby

Ruby Day
gallery

Gallery Day
book

Book Day
gum

Gum Day
bow tie

Bow Tie Day
kiss a brunette

Kiss A Brunette Day
nae nae

Nae Nae Day
bubble bath

Bubble Bath Day
blanket fort

Blanket Fort Day
offer

Offer Day