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

Other days

gum

Gum Day
get funky

Get Funky Day
bow tie

Bow Tie Day
bubble bath

Bubble Bath Day
boba

Boba Day
tulip

Tulip Day
cuddle up

Cuddle Up Day
ruby

Ruby Day
brow

Brow Day
china

China Day