Sorry about the delayed response. If I understand correctly, what you want is a display of essentially the time when the last scheduled zone finishes minus the current time, is that correct? Or do you mean just the total run time? The former will account for all pauses, delays between stations etc. The second is purely the sum of all water durations. From your description I assume you mean the former. This should be relatively easy to do, as the UI already knows the scheduled start time and duration of each station, so just need to calculate the end of the last station, and calculate the difference of that from the current time.