Quote Originally Posted by cmpgeek
i am humbled by yall's "gray matter" hehe
That ain't all that's gray!!

On the serious side, Walkenbach provides detail on how to set up rolling periods for graphs (i.e. always a six month period), in his book Excel Charts. BTW a superb resource if you work with charts much.

Or check out this from Andy Pope:

http://andypope.info/charts/Scrolling.htm

as a starting point.