Case Lapse Averages by Month

Hey all,

Having a little trouble working out an efficient formula, and I'm appealing to the collective expertise of the internetz. Essentially, the workbook I'm building is a relatively basic case management tool for which I'd like, on a separate administrative page, I'd like to compile some biographical data. This is the calculation I'm running into a wall over:

- Each page tracks a total of three months. There's no plausible way to predict case volume at this point, so simply using pre-defined ranges (e.g., B1:Bx) is out - this has been overcome, otherwise, by simply naming the entire range ("CaseDate" in 01-Jan-00 format) of the column and having other calculations which us the data call from that.

- Each page also tracks the total length of time lapsed (CaseAge) between the date the case originated ("CaseDate") and the date the case was closed ("DecisionDate"). So far, this calculation has worked marvelously.

- What I would like to do now is, on a separate page, is calculate the average of CaseAge, using only rows which contain a ("CaseDate") of a specific month (say...January 2013, for example).

Any ideas? Pivot tables are not a singularly attractive model at this point, given the overall design objective.

Thanks in advance for any input!

*le bump*

Page 4 was too quiet.