Counting Unique Data in Report

[Danielle]

I have a report that lists data, grouped by staff member, then by date.
Sometimes two dates that are the same will be listed, which is fine because
they have different data. What I cannot get the report to do is count only
the UNIQUE dates that are listed, not every line. In other words, how do I
get it to EXCLUDE hidden duplicate data? I am currently just using the COUNT
function...
the report looks something like this

DATE:
ITEMS
1/8/06
4
1/9/06
3
("BLANK" because of hidden duplicate date of 1/9/06) 5
1/10/06
1
1/11/06
1

and it counts 5 rather than what I need, 4

Any advice?

Thanks for any help you can offer!!

 

[Danielle]

I should mention that when I posted this, the formatting was changed on my
paragraph...so the dates would actually be listed as such:
1/8/06
1/9/06
1/9/06 (this one would be hidden)
1/10/06
1/11/06

TOTAL of 4 unique dates....but my report counts 5
eeeek!