In chapter 19, we add rotation to the time when it changes. While animations occur reliably when I press the time button, they do not occur reliably when the view is changed between the two tabs along the button. I added a viewDidAppear delegate method which replicates the viewWillAppear. I assume the animation was not firing because the updating of the time was occurring before the actual view was fully visible rather than after it was on the screen. Is this the correct reason?