Hi...
I have a sheet with column A containing invoice date, column B containing customer ID and Column C containing customer types (wholesaler, key account, pharmacy, etc).
My Objective is to count how many customer within a certain category (Pharmacy, wholesaler, etc) that buy from us during a certain span of date.

Let's say...
I want to count how many pharmacy that bought from us during 6th June 2012 to 15th June 2012.
PS: "If Adolf Pharmacy bought from us at 6th June 2012 and 10th June 2012, it will be counted as one."

And i would like the result on another summary sheet.

I have been struggling with this for weeks. Is this possible?

Cheers.