average if - between range

[Chris26]

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

 

[Don Guillett]

=AVERAGE(IF((HOUR(F8:F28)>=10)*(HOUR(F8:F28)<11),G8:G28))
An array formula that must be entered using ctrl+shift+enter

 

[Jacob Skaria]

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))