Since the Julian calendar was in use at the time, the anniversary is actually November 1.
I disagree. This is a case where we remember the date, not the translated version of the date. For example, Julius Caesar was assassinated on the Ides of March, (March 15) which was also the 15th day into the Roman Spring. Julius recalibrated the calendar so that spring occurred on March 1. Due to calendar drift, we see spring now as March 21, but we don't remember the Ides as a date 15 days past March 21, we remember it as March 15.