You know the situation - you experience it almost every day: When you wake up in the morning, you'll want to know the time.
Of course you could take a look at the alarm clock, but that would imply looking at the small clock on your bedside table. If you have a clock that's able to project the time on the ceiling, it's better - but still, you have to get your eyes into a state where they can focus at the numbers. This is where talking alarm clocks come in handy. But you might not have one. However, you do have a mobile phone. Why not let the phone read the time for you?