quantumleap

I am looking at footage with two time stamps, one on the left and another on the right. They are not exactly an hour in difference so I can't say it's an daylight savings error but which time stamp would be the correct one? The left time stamp is within the video and the right time stamp is typically on a black bar above the entire video. I tried to look at the manual for vivotek surveillance cameras, but I am not sure how this works. Anyone able to explain?