You may be right, Paul; I'm certainly not understanding something.

Here's what I think I'm hearing: In the CSV is some text that reads "...<date>...", with commas around it. When Excel reads the CSV, step10 reports that the date is displayed as "Mar-13" in the cell, but when he clicks on it it displays "March 13, 2013" in the formula bar. (Right, step10?) He reports this as a problem, believing that Excel is "changing" something. Me, I don't think that's what's happening; I think all that's happening is that Excel is choosing the default format for displaying dates. And I suspect that step10 has already tried changing the format of the date to suit him, then saved the worksheet again—still as a CSV—and is frustrated that when he opens the CSV again later, the date is no longer in the format he selected, but back to the original one.

You suggested some ways he could ensure that the format is set correctly (again) every time he opens the CSV. I went on to explain why a CSV can never actually retain the format from one session to the next.

So the issue (I think) is that Excel is behaving as it's designed, but step10 simply didn't understand what a CSV is supposed to be. But you say the issue is ... I'm not sure I follow it. Am I missing something, or did I just phrase it misleadingly, the first time?