Hi Marc,
I think you might have to reorganise your data table if you want 1 line
on your graph.
The left column of Date/Time values could be achieved by formatting it
as Customd/m h:mm AM/PM, then, going down the column...

1/11 12:00 PM
1/11 5:00 PM
1/11 10:00 PM
= A2 + 1 'assuming 1/11 12: PM is in A2

Then select the cell with "= A2 + 1" and fill down to get the rest of
the Date/Time values.

Then by what ever method needed copy the Y values down the column next
to the Date/time values column.

Then insert an X-Y Scatter Chart.

Ken Johnson