Lets say Islam invades the United States, and over 200 odd years...

Lets say Islam invades the United States, and over 200 odd years America is renamed, every bit of "America Culture" is destroyed and outlawed, everyone speaks arabic. "Americans" are all but wiped out...only 2-3% remain.
Then over the course of another 200yrs "secularism" slowly takes over and the Islamic Theocracy is cohort replaced, Democracy is in use, morals evolve...etc etc...
They slowly embrace "multiculturalism" and wish to celibrate everything they've become as a nation.


Now, would September 11 be an appropriate date to celibrate such an occasion?