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

Other days

prosecco

Prosecco Day
aloxolt

Aloxolt Day
get funky

Get Funky Day
gum

Gum Day
blanket fort

Blanket Fort Day
buddy

Buddy Day
raise awerness of zeus

Raise Awerness Of Zeus Day
china

China Day
boba

Boba Day
cuddle up

Cuddle Up Day