Seeing the clock saying (and flashing) 2:18 AM it tells me that the power came back on 2 hours and 18 minutes ago but I have no way of knowing how long the power was out. It could have been out for an hour, 20 minutes or just a second, I don’t know. I did find out that the actual time was 9:30 so I woke up and had breakfast. Oh, and I went around the house resetting all my clocks.