It would be nice to have the ability to schedule changes, the same way that service requests can be scheduled.
This is already possible. When viewing your list in the Change Catalog, use the calendar button to the right.
Is this what you are looking for?
OK, it seems I just can't do this for changes marked "Internal". Can we make it possible for Internal changes?
In fact, I can't seem to use the change catalog item at all when it's marked as Internal. Which essentially makes "Draft" and "Internal" the same thing.