I notice this in my trend info that reads from the clientraw extra file over a 24 hour period.
I wonder if you know what might cause the data to be off like this.
Just to answer the obvious things I can think of:
Times are in sync between PC and VP2 Console updating every minute.
My server time is also within seconds of my PC time
I did reboot the PC around 1600 hours before the first data set./