iOS 11 release date

Historical iOS GM release dates:

iOS Version Release Date Day of the week
iPhone OS 1 29th June 2007 Friday
iPhone OS 2 11th July 2008 Friday
iPhone OS 3 17th June 2009 Wednesday
iOS 4 21th June 2010 Monday
iOS 5 12th October 2011 Wednesday
iOS 6 19th September 2012 Wednesday
iOS 7 18th September 2013 Wednesday
iOS 8 17th September 2014 Wednesday
iOS 9 16th September 2015 Wednesday
iOS 10 13th September 2016 Tuesday

From iOS 5 onwards there is an obvious trend - midweek release in the third week of September. Based on that, and the move to Tuesday last year, I will go with Tuesday, September 12th as the release date for iOS 11.

Update - I was a week off. iOS 11 releases to the public on the 19th September.