Hi OBR,

Yes it is the numerical value of the dates. For instance todays date
6th May 2008 has an underlying value of 39574, that is the value
that Excel will use to make calculations or to create a chart etc.

You need to do a bit of lateral thinking to workaround it, usually
involving dummy series and dummy calculations in the worksheet.
Maybe calling your first date 0 and subsequent dates 1,2,3 etc.
you then use dummy labels or series to make your chart look right.
How you do the workaround depends on how your data is laid
out and what result you are trying to achieve, there are no real set
rules for doing this, it changes every time.

HTH
Martin


"OBR" wrote:

I performed a polynomial regression with dates and flow rates in Excel. The
result provides me wit a sixth degree equation in function of dates
(independent variable). For some reason, when I use the equation to predict
future flows the equation produces very large values. I am assuming it is due
to the numerical format of the dates in the cells. Does any one know how to
solve this issue?