On 3 August the reliable leaker Steve Hemmerstoffer announced that "as expected, #iPhone8 mass production just started," as a follow-up to an earlier tweet in which he predicted a September launch. And an internal company memo offers more specific clues to the device's launch window in September.

The memo, posted by Benjamin Geskin, names 'black out days', when staff must be present, between 17 September and 4 November. This suggests that the launch announcement will come on or very close to 17 September, and that the following eight weeks represent the product's highest-demand period, when staff will be most urgently needed in the office