Mark your calendar
The speculated date has arisen after TmoNews' mystery sources told the site that US T-Mobile employees have been forbidden to go on holiday from 20-22 September.
Apple launches tend to create very long queues and frenzied mobs, so it makes sense that a major network provider will need every hand they can get on the big day.
A 20 September release date for the iPhone 5S and 5C makes sense to us as it follows the iPhone 5's release date pattern from last year, when it too launched the week after its reveal.
Check out everything we think we know about the iPhone 5S so far to prepare yourself for the big day on 10 September.