=SUMPRODUCT(--(A1:A100="07/01/06"+0),--(HOUR(B1:B100)=10))
Sumproduct likes to work with numbers, but the tests above will return
logical values, either True or False. -- will turn the logical values into
numbers, either 1 for true or 0 for false. The first - will make a true -1.
The 2nd will turn the negative 1 to a positive 1. Negating false returns 0
(both times.)

Bob Phillips has a very useful explanation of Sumproduct. Let me dig up the
link ...
http://www.xldynamic.com/source/xld.SUMPRODUCT.html
Also, this link explains the --:
http://www.mcgimpsey.com/excel/formulae/doubleneg.html

--
Kevin Vaughn


"ChristiaanV" wrote:


Out of curiosity, what exactly are the double dashes, and what do they
do?


--
ChristiaanV
------------------------------------------------------------------------
ChristiaanV's Profile: http://www.excelforum.com/member.php...o&userid=37363
View this thread: http://www.excelforum.com/showthread...hreadid=570571