Backdrop or Background for Vertical Time Range

[buee86]

I've been searching around for this and haven't found it so I'm assuming it can't be done. What I'm looking for is a way to have a different background on the graph based on the time that the graph is displaying. For example, we're an ISP and we have peak usage hours. I would like to put a different background to represent these hours. Let's say our peak hours are from 7:30PM to 11:00PM at night. I would like to make the background of the time graph light green for these hours. I've seen ways to put horizontally shaded areas, I'm looking for vertically shaded areas. Can it be done? If so, how?