Mom just called me. I am going over to her house for coffee in the morning so they can give me a ride to my truck when I leave out tomorrow.
She had lain down to take a nap. When she awoke she looked at the clock and thought she had overslept. She rushed into the kitchen, made coffee, and then walked out onto the porch to get her morning paper whereupon she got angry thinking someone had stolen her paper (it's happened). She sat down in the living room and switched on the television. That's when she realized that she was off by 12 hours.
She just had to call and tell me about it.
I've done this sort of thing myself, thinking I had slept much longer than I have, and I really hate when that happens.