Time Intelligence Functions

Hi, Anonymous 

Based on your description, I created data to reproduce your scenario. The pbix file is attached in the end.

Table:

Calendar(a calculated table):

Calendar = CALENDAR(DATE(2018,1,1),DATE(2020,12,31))

 There is no relationship between two tables. You may create calculated columns and meausres as below.

Calculated column:
CalendarYearMonth = YEAR('Calendar'[Date])*100+MONTH('Calendar'[Date])

YearMonth = YEAR('Table'[Transaction Date])*100+MONTH('Table'[Transaction Date])

Measure:
Current year Sales = 
var tab = 
SUMMARIZE(
    'Table',
    'Table'[Customer],
    "Current Month Sales",
    CALCULATE(
        SUM('Table'[Amount]),
        FILTER(
            ALL('Table'),
            'Table'[Customer]=EARLIER('Table'[Customer])&&
            YEAR('Table'[Transaction Date])=YEAR(TODAY())&&
            MONTH('Table'[Transaction Date])=MONTH(TODAY())
        )
    )
)
return
SUMX(
    tab,
    [Current Month Sales]
)

Prior Year Next 1 Month sales = 
var tab = 
SUMMARIZE(
    'Table',
    'Table'[Customer],
    "Prior Year Next 1 month sales",
    var _customer = [Customer]
    return
    CALCULATE(
        SUM('Table'[Amount]),
        FILTER(
            ALL('Table'),
            'Table'[Customer] = _customer&&
            'Table'[YearMonth] =
            CALCULATE(
                MIN('Calendar'[CalendarYearMonth]),
                FILTER(
                    ALL('Calendar'),
                    'Calendar'[CalendarYearMonth]>(YEAR(TODAY())-1)*100+MONTH(TODAY())
                )
            )
        )
    )
)
return
SUMX(
    tab,
    [Prior Year Next 1 month sales]
)

Prior Year Next 3 Month sales = 
var tab = 
SUMMARIZE(
    'Table',
    'Table'[Customer],
    "Prior Year Next 3 month sales",
    var _customer = [Customer]
    return
    CALCULATE(
        SUM('Table'[Amount]),
        FILTER(
            ALL('Table'),
            'Table'[Customer] = _customer&&
            'Table'[YearMonth] in
            TOPN(
                3,
                FILTER(
                    ALL('Calendar'[CalendarYearMonth]),
                    'Calendar'[CalendarYearMonth]>(YEAR(TODAY())-1)*100+MONTH(TODAY())
                ),
                [CalendarYearMonth],ASC
            )
        )
    )
)
return
SUMX(
    tab,
    [Prior Year Next 3 month sales]
)

Result:

Best Regards

Allan

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