The easiest way is to use COUNTDIFF function which is part of the Morefunc
add-in, then you can use this formula

=COUNTDIFF(IF(J2:J100="employee number",IF(L2:L100<"",L2:L100)),,FALSE)

confirmed with CTRL+SHIFT+ENTER

otherwise, without Morefunc, try

=COUNT(1/FREQUENCY(IF(J2:J100="employee
number",IF(L2:L100<"",MATCH(L2:L100,L2:L100,0))), ROW(L2:L100)-ROW(L2)+1))

also confirmed with CTRL+SHIFT+ENTER

you can download Morefunc from here

http://xcell05.free.fr/

"Curtis" wrote:

This formual returns a value that counts the number of instances rather than
the number of different instances (days)

The data contains 7 values for Nov 15 and 8 values for Nov 16. This formula
gives an answer of 15 rather than 2

"Teethless mama" wrote:

=SUMPRODUCT(--(J1:J100="employee number"),--(L2:L100<""))


"Curtis" wrote:

Column J= employee number
Column L = day(s) work

I need to sum the number of different days worked by each employee (Column L
can have multiple instances of the same date)

Thanks

ce