Fairly new to excel

[eshanp970]

I am trying to retrieve number of sales done in a month vs how many of those customers presented for churn. 
Eg
Sheet1: Customers by sales date                Sheet2; Customers by churn date

            

Result: need the count of churned customers if their churn date and sales date are in the same month.
I tried using countifs with multiple criterias but throws error. Can someone help me out.

Req: 

[#2 · Accepted solution]

not sure I understand all the criteria. so you want a count for each unique customer (CRN) how many times the same date appears on BOTH sheets for that customer? And are we to assume that BOTH sheets may have many rows with that customer listed (i.e. it is a many to many comparison)?
The easiest and most straight forward method I would recommend is to create a 'helper' column on 1 sheet to do a look-up/check on the other sheet for that particular date/customer combo (a 1 if it exists and a 0 if not). Then on your summary sheet you can do a simple countif or sumif.
This could all be done together but the formula get more complicated and I would also want to know if you are using Excel 365 or an older version.