Hello Everyone

I am new here and I am a novice compared to most of you. I am hoping someone can help me and I look forward to helping others as well. I work in the construction industry and I am trying to use excel to create a simple construction schedule that calculates days +/- from a Planned schedule (Planned start, Planned finish) against an Actual schedule (Actual start, Actual finish) that has the ability to calculate a Future Schedule (Future Start, Future Finish). There are multiple scenarios that affect the Days +/- as well as the Future Schedule. Those scenarios are as follows:
1. No actual start or actual finish
2. An actual start but no actual finish
3. An actual start and an actual finish

My planned schedule does not include weekends as a workday. However, my actual schedule may show an actual start and an actual finish that land on a Saturday if my planned schedule starts falling behind to pick up some time. I am having trouble with the Days +/- calculation. I have tried multiple formulas but there always seems to be something off with one of the 3 scenarios above. I am also having trouble with the future schedule for the same reasons. Maybe the setup of my schedule is causing the problem. I do not know. Schedule.xlsxI have attached my schedule. Any help would be greatly appreciated.

Jay