Discombobulation

I'm totally in a daze today. I set my clock back the hour last night before I went to sleep. This morning, I woke up at about 10:30, and, in my sleepy haze, forgot I had already set it back and said, "Oh, that's an hour faster than it really is, why the hell am I awake at 9:30 on a Sunday?" promptly fell back to sleep and didn't wake up until about noon.

All you inventors out there, I need you to come up with something for that, some sort of marker we can put on our clocks so we know if we've already set it back during the time shift. Thank you.