Being a man known for my politically correct sensitivities and an English streak of masochism I have a solution to the problem.
I can understand sensitivities expressed here. After all we Poms do not commemorate the Battle of Hastings or any other invasion. Australia has no national holiday between June 12 and Christmas. So I commend to you 29th August. This combines two Australian sports, cricket and Pom bashing.https://en.wikipedia.org/wiki/The_Ashes#1882_origins