Help with DATESINPERIOD

Thanks for the reply from foodd  ,please allow me to provide another insight:

Hi, Quenril 

Regarding the issue you raised, my solution is as follows:

1.First I have created the following table and the column names and data are the data you have given:

2. Below are the measure I've created for your needs:

avrg = 
VAR currrunt1 =
    MAX ( 'time'[Date] )
RETURN
    DIVIDE (
        CALCULATE (
            DISTINCTCOUNT ( 'Client Meetings'[Index] ),
            FILTER (
                ALLSELECTED ( 'Client Meetings' ),
                'Client Meetings'[Date] > EDATE ( currrunt1, -13 )
                    && 'Client Meetings'[Date] < currrunt1
            )
        ),
        12
    )

3.Here's my final result, which I hope meets your requirements.

Can you share sample data and sample output in tabular format if I am misunderstanding? Or a sample pbix after removing sensitive data. We can better understand the problem and help you.

Please find the attached pbix relevant to the case.

Best Regards,

Leroy Lu

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