title: Does -[NSCalendar ordinalityOfUnit:inUnit:forDate:] not work?
body: <p>I have the following code in my program:</p>
  
  <pre><code>NSUInteger currentMinuteOrdinal = [[NSCalendar currentCalendar] ordinalityOfUnit:NSMinuteCalendarUnit inUnit:NSEraCalendarUnit forDate:[NSDate date]];
  NSUInteger passedInMinuteOrdinal = [[NSCalendar currentCalendar] ordinalityOfUnit:NSMinuteCalendarUnit inUnit:NSEraCalendarUnit forDate:passedInDate];
  NSUInteger minuteDifference = currentMinuteOrdinal - passedInMinuteOrdinal;
  </code></pre>
  
  <p>The current time is today at 6:09pm. The passed-in time is today at 4:17pm. (I'm looking at the values in the debugger so I know these values are correct.) Yet these two ordinal values always come out to the same value, rendering the 'minuteDifference' as 0.</p>
  
  <p>Does this method simply not work? Or am I doing something horribly wrong?</p>
  
  <p>Thanks.</p>