September 11th, 2001, was August 29th, 2001, in the Julian calendar used by the Russian Orthodox Church and other Orthodox churches.

August 29th in the Julian calendar = September 11th in the Gregorian calendar

Now, did you know that August 29th in the Julian calendar was the New Year's Day in Ancient Egypt?

That tradition was preserved by the first Christians in Egypt, that founded the Copt Church.

That's why in Ethiopia, the local Orthodox Church still celebrates the New Years Day on September 11th (that is August 29th in their Julian calendar).

So, 911 = New Year's Day in Ancient Egypt...