iCloudil has found a file in iOS that appears to identify the release date of upcoming firmware versions, reports 9to5Mac.
What we thought was a static file in iOS that correctly predicted the previous Saturday iOS 5 Beta 5 update turns out to be one that Apple can change remotely. Yesterday, it changed from Wednesday August 17th to Thursday, August 18th.
Or it could just me the next time it automatically will check and then automatically increments the number everytime you check for a software update. iTunes does this too...