title: iphone message center - how to get the message arrival time
body: <p>When I open the message center (by sliding it down from the top) I can see that each message is associated with "how long ago it arrived". How to get that info?
  I also have checked out and it seems that when I create a local notification with the repeatInterval the fireDate remains the same as in the original for all repetitions. 
  Thus I don't know how to distinguish between the dates of each local notification since the popups are non-modal. Any suggestions? 
  Thanks. 
  Regards, Victor</p>