Moslems have their own lunar calendar. They don’t follow the Gregorian calendar. The Battle of Vienna was fought on September 12, *not* 11. No one who recycles these articles about the significance of September 11 ever cites a Moslem source saying the date is significant. See the comment by commenter “49metal” in response to this silly article: http://www.onepeterfive.com/the-top-4-reasons-september-11th-is-significant-to-islam/
The idea that Moslems actually remember the dates of battles like Vienna and Malta is far-fetched. Modern scholars point out that Moslems didn’t much remember the Crusades until leftist/secular/alienated Westerners reminded them of it.
If you’ve bought into this hoax, please cease and desist.