Update: 1 day off it appears. Time zone?
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. We can only assume that Apple can change this on a whim so the date appears to be a target date, which we know can change. As of this writing, the target is in a week. We’ll keep you updated. (Thanks to iCloudil.com for notifying us of the change)