The final iOS 7 beta, number 6, is primed to arrive sometime next week (two weeks after beta 5), which puts the Golden Master release of the OS sometime in September, just as previously rumored. According to sources close to BGR following the sixth beta Apple will release iOS 7 Golden Master to employees and carriers first on September 5 and then to developers on September 10, which is...
Source: http://www.gsmarena.com/ios_7_golden_master_coming_sept_5_to_carriers_10_to_everyone-news-6583.php