Last week I got my third iPhone, now a 6S running on latest iOS. After a few days I discovered that the time on my new iPhone was wrong (I was late at a meeting) and was 20 minutes behind. Further investigation shows that in a day, the time gets more than three minutes behind the actual time. The settings are on automatic, the time zone is correct and I am not passing any time/date zones during the day. Restarting the device corrects this, but at the end of the day there is again a difference in time... Resetting to factory defaults does not solve the problem. Does anyone have a suggestion what could be wrong?