So here's what we know:
- iOS 7 is coming this "Fall"/Autumn, Spring for us southerners (Sept-Nov)
- Beta 5 has been released, one more expected in the next fortnight
- The iPhone 5 event was held in the third week of September, Wednesday the 12th
- The iPhone 4S event was in October and past events in June-July
- We have approximately 4 weeks to go until the week of the 10th
The week of the 10th "feels" right. That weeks Friday is ruled out only because of superstition, being the 13th of the month. Bar that, it could be any other day that week.
But its all speculation, guesswork based on past events until we hear the Dalrymple one-word verdict followed by the event invites.