Hi,

Am Tue, 8 Oct 2013 17:37:25 +0100 schrieb rbrookov:

Column 1 Column 2 Column 3
(Text) Date (in the following format)
Data (floating point)
a 9/19/2013 12:02:00 AM 6.58667
b 9/19/2013 12:03:00 AM 6.44361
c 9/19/2013 12:04:00 AM 6.32134
d 9/19/2013 12:05:00 AM 6.54321
e 9/20/2013 7:26:00 PM 10.11111
f 9/20/2013 7:27:00 PM 10.23345
g 9/20/2013 7:28:00 PM 10.54321
h 9/20/2013 7:29:00 PM 10.67890
i 9/21/2013 11:58:00 PM 3.12345
j 9/21/2013 11:59:00 AM 3.54321
k 9/21/2013 12:00:00 PM 4.11111
l 9/21/2013 12:01:00 PM 4.54321

The goal is to take an average of the Data in Column 3 for each instance
when the Date in Column 2 changes, ignoring the time.

in D1 try:
=IF(COUNTIF($B$1:$B1,B1)=1,AVERAGE(OFFSET(B1,,2,CO UNTIF($B$2:$B$12,B2))),"")
and copy down


Regards
Claus B.
--
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