Developers have spent all summer putting the forthcoming iOS 5 through its paces, which includes beta testing Apple’s new iCloud service, which can backup and restore data from an iOS device (among other things) -- which will get its first big test this week as Apple purges those developer backups ahead of a gold master for the new version.

9to5Mac is reporting that Apple has notified developers that the company will be resetting all iCloud backup data this Thursday, September 22. According to a post on the company’s developer forums on Sunday, purged backups will no longer be available, but a new one will be created after the maintenance is completed.

“On Thursday, September 22, the iCloud Backup data will be reset,” the announcement reads. “Backing up to iCloud or restoring from an iCloud backup will be unavailable from 9 AM PDT – 5 PM PDT. If you attempt a backup or restore during this time, you will receive an alert that the backup or restore was not successful. After this reset, you will be unable to restore from any backup created prior to September 22. A full backup will happen automatically the next time your device backs up to iCloud.”

The timing of this event is curious to say the least, since the official start of fall arrives the next day, September 23. Apple has yet to announce a release date for iOS 5 and iCloud, only promising “this fall” -- which could presumably include the first day of the season, although it seems unlikely the company would release iOS 5 without a new handset to show it off on.

9to5Mac theorizes that Apple may be purging iCloud backup data ahead of the release of an iOS 5 gold master, the last version traditionally seeded to developers ahead of the product release, which is widely expected sometime in the first two weeks of October.

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