Found a great starting point here:

http://www.excelforum.com/excel-form...-and-time.html

But I have a different type of data. I have columns with a start and stop time - but it is rounded to the top of the hour. Any increment within one hour counts as 1 hour and any increment that starts in one hour and ends in the following hour, counts as 2 hours. Even if it was 10:59 to 11:01. Because of this, there is a user field in each record that can have multiple rows for a user that all fall within the some interval.

I need to count the number of rows where there are overlapping rows, but only count 1 record for any given user within the interval.

This means the formula =SUMPRODUCT(--(BucketStart<=U2),--(BucketEnd>U2)) where the named ranges are my start and end time ranges and the start time is in column U will count the overlaps, but it does not only count individual users one time within an interval.

I need to compare the username (in column G) and only count 1 record for any given user, for any given interval.

In effect, I want the sumproduct formula to only count one overlap if within a 1 hour period when the same user has more than one record.

I hope someone has an idea. Thanks.