DPlot

It appears that date columns must be in the format of 01/01/2006 12:00 and not 01-01-2006 12:00. When there are dashes in the date format DPlot gets confused and reads only the time portion of the date.

At first glance this is only a formatting problem that you could correct by right-clicking on the date axis in DPlot and selecting the appropriate Date format. Unfortunately when the Add-In decides that your values are times (as opposed to date/time pairs) it multiplies your values by 24 to get from Excel's 24 hrs=1.0 to DPlot's 24 hrs=24. So your data will be all fouled up.

I'll correct the Add-In to look for "m-" in addition to "m/" in the formatting string. In the meantime you can correct the problem in DPlot by first setting the Default number format (right-click on the labels along the X axis, select "Default format"). Then shift X back to the original values with Edit>Operate on X w/ X=X/24. And finally right-click on the X axis again and choose "Date and Time".