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

Other days

hoodie

Hoodie Day
singles

Singles Day
ponytail

Ponytail Day
pampering

Pampering Day
gum

Gum Day
one

One Day
chocolate milkshake

Chocolate Milkshake Day
brow

Brow Day
tell a fairytale

Tell A Fairytale Day
bounce

Bounce Day