November 19th, 2003, 12:05 pm
It's probably just what PeteJ said. In addition to that, if you downloaded from Yahoo, then depending on how you did it, there can be line items for dividends or stock splits which can skew which date goes on which row if you are trying to merge multiple data series onto the same spreadsheet, and line them up by date.
All standard disclaimers apply, and then some.