Using specific date range from different date column from a different table

[Niels_T]

I have 3 tables: 'Credit Memo + Invoice', 'Calendar', 'Item'

I would like to take the column 'Creation Date' ('Item'), and calculate how much 'Quantity' ('Credit Memo + Invoice') of goods that have been sold in the first 3 months since the creation date.

Is there any way that I can take the sum of my 'Quantity', filter it on 'Creation Date' + 3 more months after 'Creation Date' and use that specific date range?

To make myself even more clearer:

Let's say Creation date is 01/10/2021.

I want to know through how many goods are being sold between 01/10/2021 and 31/12/2021. 

The relations between tables are as followed:

'Item' [SKU] -> [SKU] 'Credit Memo + Invoice' [Posting Date] <- 'Calendar' [Date]

[Greg_Deckler]

@Niels_T Sample data and expected output would be better. It would be something along the lines of using EOMONTH([CreationDate],3) to calculate the max date. Then you just filter between creation date and that date. Hard to be more specific. 

Sorry, having trouble following, can you post sample data as text and expected output?
Not really enough information to go on, please first check if your issue is a common issue listed here: https://community.powerbi.com/t5/Community-Blog/Before-You-Post-Read-This/ba-p/1116882

Also, please see this post regarding How to Get Your Question Answered Quickly: https://community.powerbi.com/t5/Community-Blog/How-to-Get-Your-Question-Answered-Quickly/ba-p/38490

The most important parts are:
1. Sample data as text, use the table tool in the editing bar
2. Expected output from sample data
3. Explanation in words of how to get from 1. to 2.

[Niels_T]

Expected output:

I tried the following measure:

Quantity (3 month after creation date) = CALCULATE(SUM('Credit Memo + Invoice'[Quantity (Base)]), EOMONTH('Item'[Creation Date], 3))

The thing now is that the value that I receive from EOMONTH('Item'[Creation Date], 3)), should be applied to see how many quantity of items I have in within that date range. 

So in short: 
The 'Creation Date' value should act as an indicator from where the date starts.

The 'Posting Date' values within my 'Credit memo + Invoice' need to be contained within that date range.

More detailed expected output:

I hope this is clear.

[Anonymous · Accepted solution]

Hi @Niels_T 

Please try this code.

Qunatity(3 month after creation date) =
CALCULATE (
    SUM ( 'Credit Memo + invoice'[Quantity] ),
    FILTER (
        'Credit Memo + invoice',
        'Credit Memo + invoice'[Posting Date]
            <= EOMONTH ( MAX ( 'Item'[Creation Date] ), 3 )
    )
)

Result is as below.

Best Regards,
Rico Zhou

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.