According to the folks at M.I.C. Gadget, it seems that they have heard from their sources in Foxconn that apparently the next-gen iPhones will be announced on the 11th of September 2015, which is also a Friday. Given that last year’s iPhone was announced on the 9th of September, we suppose it is close enough to be a possible date.
However it is odd that Apple would choose 9/11 to be a date to announce their products on, given the negative connotations that many Americans have towards that particular date. Also pointed out by Cult of Mac, it seems odd that Apple would share the details of their launch date with Foxconn since it really isn’t any of Foxconn’s business as to when Apple launches their product, they just need to ensure that products are delivered in a timely manner.
In any case take it with a grain of salt for now, but like we said given Apple’s previous iPhone releases, a September announcement is a possibility, it’s just that there is no specific date that we can look forward to just yet.