Comment 2 for bug 907781

Excellent. So does it work something like this?

Edit 4/5
Edit 5/5

Realize mistake, return to 4/5, undo while focus there, only local changes on that day are undone.
Edit some more on 4/5.
Go back to 5/5, undo while focus there, only local changes on that day are undone.

If so, most excellent.

Maybe this eliminates the need for allowing quitting without saving changes?