Data1 has been auto generated by using Power Query. So the end user will maintain data the way you uploaded it. The internal process will create Data1 and get your desired result. The end result is much simpler DAX Formulas as compared to my first solution.
Thank you very much for the Eye Opener (I suppose I would need to redo my Dashboards now since I would change most of the Dates field previously used to the New Table But anyway ... Thats not my problem now.
I had created a New Date Table and a Date Column to create all the necessary dates that would be needed ever and had reached to this as my current problem;