Thread:LiveandSound/@comment-25396609-20150521035735/@comment-25555436-20150523004745

It doesn't really go back in time. It was explained in a (never aired) episode. Jeremy said "return to the past", but it actually didn't. The computer instead keeps the state the world had up to 24 hours to the past, and when Jeremy rewinds back to the past, time doesn't truly go back to the previous day, but the state of the world, and everyone in it, goes back to how it was in it's previous state 24 hours before.

Basically, imagine saving a game after playing a total time of 4 hours. You later play for 4 hours more turning the total to 8. Then, you load the save back when you had played for only 4 hours total, with everything back to how it was back then. That's pretty much how it worked.

Of course, this is also the reason their memories get "deleted"...which they don't, but more like they were never created in the first place. As for why their memories don't get deleted like everyone else's, Jeremy put their memories's datas on the computer, so they stay intact after rewinding.