The short answer is nobody except those working at Apple knows.
Although it wouldn't be a stretch to guess between the 2-3 week cycle. My best guess is Aug 18th or 25th
in exactly 178 hrs 52 mins 18 seconds as of this post, i am without a doubt correct so do not dare to question my eta.
i work at apple on the ios dev team & make $59.50/hr so im a rich typical stuck up ***hole like 99% of rich people, also this is the internet, believe every, single, word you read