Hi,

With your start date in E1 and end date in f1, try this

=SUMPRODUCT((B2:B7=D1)*(B2:B7<=E1)*(C2:C7<""))

or if your looking for cells in column c that have a date try this

=SUMPRODUCT((B2:B7=D1)*(B2:B7<=E1)*(ISNUMBER(C2:C 7)))

Mike

"Jul" wrote:

I need to find quantity of Letters between some period of time (one week)
from 21-09-09 until 27-09-09, which are not replied (Cells with Reply date
are blank)

Letter No Received Date Reply Date
L-255 21-09-2009
L-256 23-09-2009 25-09-2009
L-257 25-09-2009 27-09-2009
L-258 21-09-2009
L-259 22-09-2009 25-09-2009
L-260 26-09-2009