Alternate Ordering of Attributes in SSAS

Sometimes we need to display attribute members in SSAS in a different order than the order of its name or key. For this purpose we have the option to use one of its attribute's name or key. However, in some cases changing the order may break some calculation logic which depends on the initial order. The new ordering may also be inconvenient for writing MDX as using some functions of the language is easier (at least conceptually) when thinking of sets in ascending order. The best example which we can use to illustrate this problem is the Date dimension. While in most, if not all, cases the Date dimension is ordered in ascending order, sometimes users prefer to see the most recent date first and request us to change the order to descending. Doing so invalidates many time intelligence calculations like rolling and parallel periods, etc. Furthermore, fixing those requires inverting numbers to negative, or avoiding the use of functions like ClosingPeriod. All in all, a "small" change can lead to a big problem. We can, however, accommodate our ignorant users (which unknowingly get the benefit of reading default time series charts backwards - from right to left - when dragging-dropping descending dates in Excel, for example) without changing too much in our scripts. A little trick in the modelling can help and it is the reason for writing this post.