There are two ways to restore your calendar data. To start, please be aware that our backups pull over your individual calendar events but they are not sorted by the date they were backed up like a traditional backup system. Your backups are not organized like: "July 26, 2013 backup", "July 27, 2013 backup" etc. Instead, each individual record that is backed up is accessible on its own. With that said, here are the two ways to restore your data (including events that were backed up and later deleted from your calendar in Google Apps).
1) You can restore a single record:
Go to the Google Calendar service, and you can use our search feature to search for the name of the event. Once you find it you can then download or restore it.
2) Restore the entire contents of your backup:
When you go to your Calendar service archive, you can select "Restore All" to restore every calendar event that's ever been backed up by us back to the Google Calendar account it was pulled from. This method will also restore events that have been deleted from Google Apps, so long as they were backed up once before being removed from Google Apps.