Hi
I have the following data
Col-A Col-B
1/10/2009 10:20 0.006
1/10/2009 10:22 0.007
1/10/2009 10:24 0.006
........
1/06/2010 15:00 0.015

etc
What I would like to be able to do, is to calculate the average of the
vaules in Col B only between certain time periods i.e. 2am and 4am for each
day in the data set

Any help appreciated.
Many Thanks
Chris

=AVERAGE(IF((HOUR(F8:F28)=10)*(HOUR(F8:F28)<11),G 8:G28))
An array formula that must be entered using ctrl+shift+enter
--
Don Guillett
Microsoft MVP Excel
SalesAid Software

"Chris26" wrote in message
...
Hi
I have the following data
Col-A Col-B
1/10/2009 10:20 0.006
1/10/2009 10:22 0.007
1/10/2009 10:24 0.006
.......
1/06/2010 15:00 0.015

etc
What I would like to be able to do, is to calculate the average of the
vaules in Col B only between certain time periods i.e. 2am and 4am for
each
day in the data set

Any help appreciated.
Many Thanks
Chris

With start datetime in cell C1 and enddate time in cell D1 try the below
array formula. Press CTRL+SHIFT+ENTER to enter the formula. If successful in
'Formula Bar' you can notice the curly braces at both ends like "{=<formula}"

=AVERAGE(IF((A1:A10=C1)*(A1:A10<=D1),B1:B10))

--
Jacob (MVP - Excel)


"Chris26" wrote:

Hi
I have the following data
Col-A Col-B
1/10/2009 10:20 0.006
1/10/2009 10:22 0.007
1/10/2009 10:24 0.006
.......
1/06/2010 15:00 0.015

etc
What I would like to be able to do, is to calculate the average of the
vaules in Col B only between certain time periods i.e. 2am and 4am for each
day in the data set

Any help appreciated.
Many Thanks
Chris