This is an ongoing glitch with the tournament times. I'm really surprised that Microsoft has not designed a patch for it. I have logged out of game, logged off PC, and still it happens. I was playing earlier so I decided to test it and sure enough it added 5 hours to my time (the time that I was not playing). There is no actual shut down timer option which seems like it could be an easy fix, but I'm not about to start DOSing around with my hard drive over this, potentially exposing myself to malware, when it's clearly not my problem to solve it's the gamemakers'. It is disheartening especially if one likes to play against the clock/oneself. I know it's happening to other players because no one plays for 13+ hours.
This is the closest thing to a forum that MS has for this problem, it's been going on for a long time. Today was the first time I've seen an "Independent Advisor" with the windows logo. A lot of us are playing because it's a straightforward game and may not be so tech savvy. As for restarts, I've done those as well. It doesn't seem to affect their clock - maybe because it's being stored in the Cloud.
thanks for your explanation, i did find the powershell app.