title: SAS Months between two time attributes
body: <p>I have two date variables:<br>
  A, its format is 30APR2013<br>
  B, its format is 04/2011.</p>
  
  <p>I want to calculate the months between these two times and use: <code>Month_Diff=INTCK('MONTH',A, B);</code></p>
  
  <p>It is wrong and only returns missing values for the difference. </p>