Problems with sumproduct and dates

[Kreller]

No - no other errors. I tried with using a reference to another cel
containing the date like this :

=SUMPRODUCT(--(N$3:N$1000="Møde");--(BX$3:BX$1000=A2))

Where the date 18-10-2004 is in cell A2 and I works. I think it
because when I write the date in the cell it is translated into som
sort of datevalue and then it doesn't correspond with the formulastrin
where I write bx3:bx1000="18-10-2004". I don't know whether that is to
speculative, but the evidence point in that direction as it works no
with the reference to a cell containing the date instead

 

[Dave Peterson]

I tend to stay away from datevalue() and use =date().

=datevalue("11/12/2004")
may mean Nov 12, 2004 or Dec 11, 2004.

but there's no doubt with:
=date(2004,11,12)

You may want to try that version.