I don't quite understand why you would need two dates. Does a given row in the underlying data really have different expected vs. actual dates, or are those dates the same (at the week aggregation that you have in the view)? In the latter case, then you'd only need one of the dates in the view and would get the proper result. In the former case, I'm not sure how I'd set this up, could you post a packaged workbook (.twbx) with some sample data?
Yes a given row in the data has different expected vs actual dates. I talked to a Tableau expert and he said I need to adjust it with a custom SQL statement before I bring it into tableau.