DAX PowerPivot Arbitrary Time Intelligence with Fact tables containing Future Data

One thing I love about PowerPivot is the Time Intelligence feature. Aspects of Time Intelligence appear non-intuitive at first, but with practice, it becomes clear. This is all very well if you have nice, clean Time Intelligence requirements, such as Year to Date, Month to Date, and so on. However, what happens if you have arbitrary or variable date handling requirements? What happens if these arbitrary requirements are complicated by the additional factor where your fact table contains future facts in addition to previous facts?