I no longer see the clock or the name of my service (Lucky) on my external screen of my mobile phone, just an icon of an hourglass and the words Time Is Up; however, I'm not sure if this is a service issue or a phone one as I recently had a major power outage in my area and was messing around with the Timer and Stopwatch options.
Not 100% sure, but i believe this is an iPhone on which you are having the problem on. And I believe this is because of the screen time, as usually it displays the hour glass flipping and saying that the time is up, enter passcode something like that.
