Count Unique Values within date range

Forum Guru's,

I'm having difficulty figuring out how to do some counting as the column I would like to count has duplicates and I simply need the unique values.

Below is the formula I use to simply count how many total records fall within the specified date range. The date range is contained in I7 as the start date and K7 as the end date.

The data being counted is housed in a separate tab, Weekly Pre-sale Physical.

=COUNTIFS('Weekly Pre-sale Physical'!$I$3:$I$173,">="&I$7,'Weekly Pre-sale Physical'!$I$3:$I$173,"<="&K$7)

In column B of that tab, we keep a list of serial like numbers (29730) that I would like to count, based on the date range above and only unique values as we may list that serial number twice.

I've tried all of the Unique Value formula's I can find but can't seem to accommodate for the "date range" as described.

Any thoughts? Thanks in advance!

Hmm.. Probably a Pivot table would be best solution...

However, didn't quite get what you should have for inputs and outputs so tra look for your own based on this example:

Thanks, I should spend some more time learning how to use pivot tables.

The goal however is to report the data on the Monthly Survey Report tab Column C row 13. In this report, we are at times surveying multiple addresses for a single opportunity. I'm trying to calculate the number of opportunities within the date range.

Holly Smokes! Works like a charm! Thank you!

Daddylonglegs,

I've just used your formula to solve my own problem. You have saved me manually counting how many unique bits of data there were in 1068 twelve month periods. I cannot tell you how happy you have made me. Thank you so very much.

Thanks daddylonglegs! You made me aware of the frequency function, which I think I will be using a lot in my reporting.