Apple is likely to release iOS 8 beta 4 to developers on Monday, July 28. The company released iOS 8 beta 3 on Monday, July 7.
Last year, iOS 7 beta 4 was released 21 days after iOS 7 beta 3. In 2012, iOS 6 beta 4 followed iOS 6 beta 3 after the same number of days.
Our Apple source confirms that July 28 is the date for the next release. However, they note that this date could be moved forward by one week. In this case, iOS 8 beta 4 would launch one week from today, on July 21.
First unveiled on June 2, iOS 8 should be released to the public in September, alongside OS X Yosemite. It features new Photos and Health apps, improved iMessages, and much more.
In 2013, Apple released six iOS 7 betas before launching the GM, or gold master edition. One year earlier, iOS 6 went through four betas before the GM was handed to developers.
The longest development process for an iOS release occurred in 2011 with iOS 5. That year, there were seven betas followed by the GM.
For more on iOS 8, see: Apple adding iTunes Extras for HD movies across multiple platforms, including iOS 8, The Fleksy keyboard app will support over 40 languages when Apple releases iOS 8, and Siri Offers Some Funny Quips Concerning iOS 8, WWDC.