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

Other days

artists

Artists Day
bonang

Bonang Day
nae nae

Nae Nae Day
frozen yogurt

Frozen Yogurt Day
coffee

Coffee Day
boy friend

Boy Friend Day
tell a fairytale

Tell A Fairytale Day
aloxolt

Aloxolt Day
polyamory

Polyamory Day
gum

Gum Day