title: Comparing NSDate and UIDatePicker ERROR
body: <p>Trying to form an if statement which compares the current date on the left to the date chosen in UIDatePicker on the right, I think this is the right code I was given by a fellow Stack Overflow user, they shouldn't be able to perform this action, and they can't but I need to create a pop-up telling them why not: </p>
  
  <pre><code>  //Get the current date
    NSDate *pickerDate = [self.datePicker date];
  
    //Unable to set notification for same day
    //[datePicker setMinimumDate:[NSDate date]];
  
    self.datePicker.date  = [NSDate date];
    if ([pickerDate compare:datePicker] == NSOrderedAscending) {
  
      UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Something wasn't right." message:@"That did not work and your alarm was not set." delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
  
      [alert show];
  }
  </code></pre>
  
  <p>I am receiving the following error from implementing this:</p>
  
  <blockquote>
    <p>Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UIDatePicker timeIntervalSinceReferenceDate]: unrecognized selector sent to instance 0x10b9373a0'</p>
  </blockquote>