A lot of times I plot hourly or even 15 minute data. Unless if I am doing a
simple line graph (which can be done with an XY plot) Excel will only plot
the data as daily data. The only way to get around it is to change the X
value data (date/time stamp) to regular text data. I want to be able to plot
the flow on a line graph and the rain on the same graph (second y-axis) as a
bar graph.

Sample Data:
A B C
Date Time Flow(mgd) Rain(in)
2/13/2007 0:15 1.2 0
2/13/2007 0:30 1.3 0.1
2/13/2007 0:45 1.5 0.2
2/13/2007 1:00 1.1 0