I am looking for a widget to help me monitor specific interfaces for bandwidth utilization over the course of 7 days to 1 month. Do you have anything you use to do this and willing to share?
I may be misunderstanding your need, but would performance analyser not do what you need?I realise it isn't a widget per se, but you can save the perf stack and come back to it at any point to see what's what.
If you are looking for a graph over a period of time you may want to try adding the widget called Custom Chart. It would appear like this. You can select the time period and interfaces.