One of the questions you often get is how to calculate a customers age on a certain date. Luckily Chris Webb published a great example: http://cwebbbi.wordpress.com/2014/06/09/calculating-ages-in-mdx/.
I made a small extension to this by making it level aware, this means you can also use it at year, semester, quarter and month level.
To make it level aware I use the .Level.Ordinal extension on the Currentmember. This returns the Level of the member within the Hierarchy (0 = All, 1 = Year, 2 = Semester, 3 = Quarter, 4 = Month, 5 = date).
