"Bob Phillips" wrote in message
...
See

http://www.xldynamic.com/source/xld.SUMPRODUCT.html
Multiple Condition Tests

for a full explanation.

--

HTH

RP
(remove nothere from the email address if mailing direct)


"Ron" wrote in message
...
I have been seeing "--" in formulae but cannot find an explanation of
what
it is or does.

Example: =SUMPRODUCT(--(MONTH(B2:B13)=1), C2:C13)

Thank you very much. It now makes sense.
Ron