Could you perhaps include a sample of what you are looking for i.e. are getting and am expecting. It sounds like you can do with an amulgamation of maybe a Master Calendar and some nifty Set Analysis, but without knowing exactly what you are after it is difficult to propose a possible solution.
I'm not sure if it's worth attaching a file as the one I have is huge and likely not helpful. I will if this doesn't clear things up.
I have several fields. One field, called "Data as of", has four unique dates in it: 3/31/2011, 6/30/2011, 9/30/2011, and 12/31/2011. Each row in the file has one of the four dates attached to it, and each date is repeated ~300 times within the "Data as of" field.
I want the end user to be able to somehow select two of these dates, preferably from a dropdown menu. I then need to run calculations on just the data corresponding to these dates (percentage change, etc.).
Thanks for any help.