Well, I quickly glanced through the whole thread. And every time there were two mentions of the same daypower being available, they were posted 12 hours apart. (There were a few discrepancies, but I guess it's because the page loaded right before the hour ended and that person only noticed it or posted about it when it was already too late)
So, I'm pretty sure the theory is correct for the daypower. And for normal powers, we already have three examples, so I think it's correct too. It's funny we didn't notice that before!
The thing that's going to be the most confusing to some people is that everything is tied to the New York time zone. A power is only active twice over the course of one day in New York! Everything will be shifted if they live in another time zone...