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

Other days

cursing

Cursing Day
boba

Boba Day
gum

Gum Day
martini

Martini Day
bonang

Bonang Day
frozen yogurt

Frozen Yogurt Day
pumpkin

Pumpkin Day
blanket fort

Blanket Fort Day
ruby

Ruby Day
kale

Kale Day