Display many hours in waveform graph

I'm testing a way to collect the output voltage from a power supply into a waveform graph and display the values in relation to absolute time over a few hours.
My problem is that I can only see the last few seconds in the graph. In addition, the absolute time on the right side of the x-axis is correct, but as the time is running, the left side of my x-axis show a time that is in the future. This should have been the time when the relating y-values had occured. 
Do you have any ideas how to solve these challenges?
Attached you can find my VI.
Attachments:
Test2.vi ‏125 KB

You could use an x-y graph like the attached example.
Andrew Alford
Production Test Engineering Technologist
Sustainable Energy Technologies
www.sustainableenergy.com
Attachments:
value vs time.vi ‏14 KB

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