We occasionally have tickets that go beyond 6 months old (longer projects, things waiting for the new fiscal year, etc) and they slip out of the default ticket view and the agent forgets to close the ticket when it's actually resolved. On Spiceworks, we had the ability to edit the Resolved date in these instances so that the ticket metrics were not thrown off (and of course we had internal procedures around this, reminders, etc.).
It would be great to have this feature available in Fresh Service. We didn't use it often, but used it enough where it's absence is missed.