If you’ve ever wondered how many days it takes between iOS betas to be released and the days final version have been out, you can now see it all in one place. Will Hains has painstakingly graphed all the beta and final release dates on his blog:
For iOS betas, iOS 5.0 had eight betas but iOS 5.1 beta 3 was the longest at 38 days:
As for final releases, iOS 3.1 was the longest release at 285 days before another version was released by Apple:
Currently iOS 6 beta 2 is available to developers. The final version of iOS 6 is set to be released this Fall.