I don't understand what you mean by "shifted". The first date on the graph is 5/25 and the first date in the string array is 5/25. All of the other points in the graph seem to agree with the strings as well.
On my computer which is running WIN2000 the first date in the array is 5/26 but the plotted data is at 5/25, and all of the subsequent dates are similarly shifted (see attached JPEG file). I checked my system date/time and it was indeed July 2. I even had someone else run this app on another computer and they got the same results as I did. ??????????
Since the dates are the same when I run your VI (and with the same OS and LV version), I can only guess that it might have something to do with your local time/tdate settings.