MDX: ParallelPeriod Is Not Calendar Aware (Part 2)

In the last post, we explored the ParallelPeriod function in a bit of detail and then used a contrived example to highlight a particular edge case that needs to be explicitly handled when the number of children differs between the 2 periods. Specifically, we looked at a prior month calculation and showed that calculating the same date in the prior month for 3/31/2007 returns NULL. As we concluded, this is because ParallelPeriod works by calculating the same relative position (like the Cousin function) and there's not a corresponding 31 date in the previous month (February).