It looks like the iPhone 7 will be unveiled in the first week of September. Noted leaker Evan Blass posted on Twitter that the upcoming iPhone will go up for pre-order from September 9, with an earlier tweet stating that the phone will release on September 12.
Confirmed: Pre-orders start on the 9th. You can extrapolate the launch event date from there. https://t.co/gwoPzIM1dI— Evan Blass (@evleaks) July 28, 2016
If Apple sticks to its timeline, we may see the iPhone 7 announcement on September 6 or 7. Last year, the iPhone 6s was announced on September 9, a Wednesday, with the phone going up for pre-order three days later on September 12.