Show difference between planned and actual progress

Progress bar should have two configurable parameters. First: number of units (bytes/chars/words/paragraphs). When this is set, you see how much you wrote already. Second: due date. when this is set, you see how much time is left to finish your work.

If BOTH parameters are set, you should see your current progress compared with planned progress for current day (calculated from "units per day" value).

Additionally it can be possible to enable text label for progressbar what shows one of following: "units left", "days left (or overdue)" or "units left for today (or overdue)"