Count unique in column 1 within a date range in column b

[Montanes]

Hi, and thank-you in advance for your assistance...

Column 'A' contains a set of order numbers. These may be duplicated if a sales order has more than 1 product.

Column 'B' has the date of sale in every row regardless of whether the order number is duplicated or not.

So, i am trying really just trying to count how many sales have been made in each month but i cant count the duplicates.

I can do this if i use a helper column but hopefully trying to avoid that if possible.

 

[Fluff]

In D2 down put the start date of the month & use this in E2

=ROWS(UNIQUE(FILTER($A$2:$A$100,($B$2:$B$100>=D2)*($B$2:$B$100<=EOMONTH(D2,0)))))

 

[Montanes]

In D2 down put the start date of the month & use this in E2

=ROWS(UNIQUE(FILTER($A$2:$A$100,($B$2:$B$100>=D2)*($B$2:$B$100<=EOMONTH(D2,0)))))

That works perfectly, thank-you

 

[Fluff]

You're welcome & thanks for the feedback.