Month to Month Flow Calculation

hi Transho 
The reason you are seeing blanks specifically in April, June, September, and November is due to the exact date-shifting mechanics of the DATEADD function interacting with your "End of Month" snapshots. When DATEADD shifts a date back by one month, it attempts to match the exact day number. 

1. When evaluating May, your date is 5/31/2025. DATEADD attempts to shift this back one month to 4/31/2025. Because April only has 30 days, DATEADD automatically adjusts to the last day of the month, returning 4/30/2025. Since you have data on 4/30/2025, the calculation works perfectly.
2. However, when evaluating April, your date is 4/30/2025. DATEADD shifts this back exactly one month to 3/30/2025. Because March does have a 30th day, it does not adjust to the 31st. Since your March data was recorded on 3/31/2025, DAX finds absolutely no data for 3/30/2025, resulting in a blank.

This exact same logic applies to June (evaluating May 30 instead of May 31), September (evaluating Aug 30 instead of Aug 31), and November (evaluating Oct 30 instead of Oct 31).

Can you try one of these DAX to see it works or not?

Flow Bucket - 02 :=
DIVIDE(
    [Count Bucket - 02],
    CALCULATE(
        [Count Bucket - 01],
        PARALLELPERIOD('Calendar'[Date], -1, MONTH)
    )
)

or 

Flow Bucket - 02 :=
DIVIDE(
    [Count Bucket - 02],
    CALCULATE(
        [Count Bucket - 01],
        PREVIOUSMONTH('Calendar'[Date])
    )
)

If this helped, please consider giving kudos and mark as a solution

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