counting unique customers in a list by a specific date range

**perducci** · 03-07-2012, 10:45 PM

[DIFFICULT] I have a list of customers that have made orders on several different dates. I want to count the number of unique customers for a specific date range.

the equation I use below doesn't work and I'm not sure why.

=SUM(IF(AND(FREQUENCY(MATCH(B2:B13,B2:B13,0),MATCH(B2:B13,B2:B13,0))>0,E2:E13>=K3,E2:E13<=K4),1,0))

B2:B13 refers to the customers
E2:E13 are the dates of the orders
K3 and K4 are the date range

See the attached spreadsheet, thanks

**perducci** · 03-07-2012, 11:13 PM

By the way, this equation works to count all unique values in the range, regardless of the date:

=SUM(IF(FREQUENCY(MATCH($B$2:$B$13,$B$2:$B$13,0),MATCH($B$2:$B$13,$B$2:$B$13,0))>0,1,0))

Any insights or ideas?

**perducci** · 03-08-2012, 01:05 PM

=SUM(IF(FREQUENCY(IF(INT(E2:E13)>=K3,IF(INT(E2:E13)<=K4,IF(D2:D13=0,IF(B2:B13<>"",MATCH(B2:B13,B2:B13,0))))),ROW(B2:B13)-ROW(B2)+1),1))

and press CTL + SHIFT + ENTER