We have a possessed clock.
We purchased this clock for our home theater in our previous house here in Ashburn. My wife and I had developed a bad habit of staying up too late playing video games together. We'd lose track of time and stay up WAY later than we had intended.
We searched around a bit for a clock to hang on the wall that could be seen in the dark while we were watching movies or playing video games. We only found ONE clock that was flat, wall-mountable, and lit-up. It has an alarm (why I don't know) and came with a small remote control for setting the time, setting the alarm time, and turning the alarm on and off. It's an IR remote, so it needs a line of sight from the remote to the clock.
Well, I set it up in our home theater here in our new house in Ashburn. I set the time. I turned the alarm off. The next day, I went to the basement and the time was WAY off. I just figured it had something to do with me securing the power to install some light switches, so I reset the time and left it at that. The next day, I went to the basement and the time was WAY off AGAIN. This time, I hadn't done any electrical work in the house. I thought it was weird, but I reset the time on the clock again.
This cycle repeated a few more times before I finally witnessed the clock going on independent ops while I was actually in the room. Sometimes, out of the blue, it just starts doing this...
...and then it stops again and resumes normal operations.
It's very frustrating. For a while there, I just unplugged it and didn't use it at all. Then I figured it did have SOME utility. Even if the indicated time on the clock is WRONG, I can still use it to figure out the elapsed time from when I went down cellar and made a mental note of what time the clock said it was until the present indicated time.
What else could be causing it to do this? EMI on the power line? Some other hidden IR transmitter that transmits both the hour change and the minute change signals commencing at the same time for the same duration? Is it just bad circuitry in the clock itself?