Thank you, Barnard, Sandy., and Gary's Student for expanding my knowldedge
of Excel. I was able to address my problem successfully using a combination
of Index and Match coupled with the briilliant insight of combining the date
and reading (thank you Bernard!). You al lare a wonderful resource.

Thanks again for your helopful suggestions.

Ray Wright

"Ray Wright" wrote in message
...
I have a large dataset (about 55,000 records) that consists of instrument
readings taken at different times on different days (between 24 - 40
readings per day). The data is in the format: Col A - dates; Col B - times
(24 hour clock format); and Col C - instrument readings.



I want to extract (on another worksheet) the maximum instrument reading
per day and the time of that reading (Col A - dates; Col. B - max reading
for the date in Col A; Col. C - time of that reading). I have
successfully extracted the maximum instrument reading with the array
formula:

{=MAX(IF(Sheet1!A1:A55000=A1,Sheet1!C1:C55000))}



However, I have not been able to extract the time of the maximum reading.
Is the solution come combination of INDEX and /or MATCH and/or OFFSET?
Any help appreciated.



I am using XL2002.



Ray Wright