Comparing Dates between Dimensions

You can use MathML to compare dates in dimensions. For example:

<?xml version="1.0" encoding="utf-16"?>
<Calculation>
   <Expression>
      <math xmlns:mathml="http://www.w3.org/1998/Math/MathML">
         <lambda>
            <bvar>
               <ci>x</ci>
               <ci>y</ci>
            </bvar>
            <apply>
                <minus></minus>
                <ci>x</ci>
                <ci>y</ci>
             </apply>
         </lambda>
      </math>
   </Expression>
   <RHSVariable name="StartMS.Actual" identifier="x"></RHSVariable>
   <RHSVariable name="StartMS.Plan" identifier="y"></RHSVariable>
</Calculation>