Calcalate Customer Retention Rate

[prabunakil]

Hi I need help. 

i have data like below:

Customer ID	Join Year	Purchase Date
1	2016	01.02.2017
2	2017	01.02.2017
2	2017	01.02.2018
2	2017	02.02.2019
3	2016	28.01.2016
3	2016	15.01.2017

I want to calculate number of customer who no purchase more then five month.

Based on the table provide. The answer should be:

Customer ID: 1 and 3. 

How to calculate based on this.

[gn_marvs1989]

If you just wanted to show that in a chart or table, you can just use a set analysis on the expression:
count({<Purchase Date={"<$(=AddMonths(Today(),-5))"}>} Customer ID )

[pradosh_thakur]

Make sure [purchase date] is in date format and not string.

count(distinct {<[Purchase Date]={">$(=AddMonths(Today(),-5))"}>} [Customer ID] )

[prabunakil]

 Date(Floor( Date(AddedDate)),'DD/MM/YYYY') as PurchaseDate,

My Purchase Date is as per above. 

[prabunakil]

I follow ur dimension and i getting as below:

 

[prabunakil]

Hi, i am still unable to calculate it.