Something like this should work for you:

In say, T3:
=IF(COUNTA(P3,R3,S3)<3,"",SUMPRODUCT((MAIN!$A$10:$ A$4999=P3)*(MAIN!$A$10:$A$4999<=R3)*(MAIN!$B$10:$ B$4999=S3))

where P3, R3 houses the start and end dates,
S3 contains the client, eg: A

Adapt the ranges to suit
--
Max
Singapore
http://savefile.com/projects/236895
xdemechanik
---
"capt" wrote:
Below is a small part of the table. I need to count each client (col B)
relative to the dates.
ie between 5-sep-07 and 10-sep-07
client A = 4
client B = 3

A B C D
Date Client Hours Total
5-Sep-07 A 5:20 5:20
7-Sep-07 B 5:15 10:35
8-Sep-07 A 10:05 20:40
9-Sep-07 B 0:35 21:15
9-Sep-07 B 7:40 28:55
9-Sep-07 A 0:15 29:10
10-Sep-07 A 0:15 29:25
and so on.....