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

Other days

kale

Kale Day
bonang

Bonang Day
hoodie

Hoodie Day
kiss a ginger

Kiss A Ginger Day
buddy

Buddy Day
stud

Stud Day
lost sock memorial

Lost Sock Memorial Day
chocolate milkshake

Chocolate Milkshake Day
believe

Believe Day
bow tie

Bow Tie Day