title: MDX SSAS 2008 Last year calculation - Leap year issue
body: <p>I have calculation which calculates the value from previous year, realized in following way:</p>
  
  <pre><code>([Measures].[SalesAmount LY], Leaves([Time])) = 
  (
       PARALLELPERIOD
       (
            [Time].[Year - Month - Day].[Year],
            1,
            [Time].[Year - Month - Day].currentmember
       ), 
       [MEASURES].[SalesAmount]
   )
  </code></pre>
  
  <p>I am doing it this way, because using only PARALLELPERIOD results in incorrect total calculations when selecting only some months for example. And it works just fine. </p>
  
  <p>However, now I am facing following issue with leap year:</p>
  
  <pre><code>Month         SalesAmount  SalesAmount LY
  ------------- ------------ ---------------
  January 2012  1000
  February 2012 1100         --Leap year - 29.February
  January 2013  1200         1000
  February 2013 1300         1050
  </code></pre>
  
  <p>The missing value (1100 - 1050 = 50 in this case) is exactly equal to the value from 29.2.2012.</p>
  
  <p>Does anyone have an idea how to solve this issue? How to get leap year working correctly, while still maintaining correct totals behavior? Any help would be greately appreciated.</p>