Oops, it doesn't look like 'batter the wookie day' is a national day..

Other days

ponytail

Ponytail Day
singles

Singles Day
prosecco

Prosecco Day
bow tie

Bow Tie Day
hannah

Hannah Day
cursing

Cursing Day
brow

Brow Day
youth

Youth Day
eat what you want

Eat What You Want Day
reading

Reading Day