Late portal decay time
To date, portals have decayed exactly 7 days after they were deployed. I know and utilise the decay times of around 50 portals in my area and have groups deployed that normally decay at regular 3 minute intervals. Last weekend this decay time was delayed by anything up to 4 minutes, occasionally snapping back to real time before drifting again. Last night my first portal decayed 24 minutes late, the second didn't decay until after the ninth, the eleventh waited until the very end and decayed 54 minutes late.