The creation date and edit date are initially the same. However, as you start to edit, the edit date does change, at least it is for me. If you are not seeing this, how is the edit tracking configured on your service? I have track edits enabled and that's it.
Currently, the time filtering is not that sophisticated and there's not really any functionality for reviewing edits. This is an area we're currently working on. You may have noticed an option called Sync on the item details page of the service. This allows for disconnected editing with synchronization. However, sync will track edits in both disconnected and connected scenarios. The server exposes sync, but the client apps still need to catch up.
Thanks,
Mike