There is a known problem where people's clocks for the rumble say different times. They are working on it. No matter what your clock says, the rumble lasts 24h. In our Guild the captains timer was correct since he was the one who started it.
We found on the iPhone side if you kill the game and restart, the timer corrects itself. It seems to drift over time for sure.
I'm captain in my guild and I was getting incorrect time (unless I looked at real clock). so not all captains get correct time
