How do you count # of months *complete* if there are not lines in your dataset for all months?

[kressb]

I need to count "months complete" when Fiscal Year is July 1 - June 30.

Fiscal Year 2020 is complete. Months Complete = 12

Fiscal Year 2021 is not complete. Months Complete = 10 (July-April)

"Total" should equal 22 (12+10)

Problem is there is not necessarily data for every month, ex:

I have tried: 

Var _Num = DistinctCountNoBlank(Amounts[MonthYr])   - returns 3

Var _Num = Calculate(DistinctCountNoBlank(Amounts[MonthYr]),Allselected()) - returns 9 no matter what the column shows

Is there any possible way to do this?

Relationships between tables:

[DataInsights · Accepted solution]

@kressb,

Try this measure:

Count Months = 
VAR vCurrentYear =
    MAX ( Dates[Fiscal Year] )
VAR vMaxMonthYrInCurrentYear =
    MAX ( Amounts[MonthYr] )
VAR vMaxYear =
    CALCULATE ( YEAR ( MAX ( Amounts[MonthYr] ) ), ALL ( Dates ) )
VAR vMonthCount =
    CALCULATE (
        DISTINCTCOUNT ( Dates[Fiscal Month] ),
        Dates[Date] <= vMaxMonthYrInCurrentYear,
        ALL ( Dates ),
        VALUES ( Dates[Fiscal Year] )
    )
VAR vResult =
    --if the current year is not the latest year, then the current year is complete (i.e. 12 months);
    --otherwise, count the number of months in the current year that are <= the latest month of the current year
    IF (
        vCurrentYear < vMaxYear,
        12,
        vMonthCount
    )
RETURN
    vResult