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AlB's avatar
AlB
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7 years ago
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SAMEPERIODLASTYEAR(DATESYTD( )) different from DATESYTD(SAMEPERIODLASTYEAR( ))??

Hi all, This came up as I was trying to answer this post by hbolo (no need to read it to answer this question). Here is the pbix We have a Date table with dates between 01/01/2018 and today (Jan 3...
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  • marcorusso's avatar
    marcorusso
    7 years ago

    This is just another case where the Time Intelligence functions don't work as expected because the Date table is wrong.

    Remember: Time Intelligence functions are guaranteed to work *only* if the Date table is "complete" - meaning you need all the dates until the end of the year.

    Not doing that, what happens is that the year 2019 seems made by 15 days, so if you include all of them than it seems you have an entire month, or an entire year.... You are violating the assumption made by Time Intelligence and you cannot trust any result at that point.

     

v-lili6-msft's avatar
v-lili6-msft
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7 years ago
hi, AlB I asked the Power BI TA team about this question. and if there is any feedback, I'll update it right here. Best Regards, Lin
  • AlB's avatar
    AlB
    Icon for Community Champion rankCommunity Champion
    7 years ago

    Hi v-lili6-msft

    Thanks very much. I look forward to hearing from them. 

      • Zubair_Muhammad's avatar
        Zubair_Muhammad
        Icon for Community Champion rankCommunity Champion
        7 years ago

        AlB

         

        Very interesting

         

        I remember you found a bug before as well  :smileywink:

        I am not sure why this is happening

        but if we use following we get correct results even with the last date.

        YTDPreviousYearRevenue = 
CALCULATE (
    SUM ( Revenue[Revenue] ),
    SAMEPERIODLASTYEAR ( DATESYTD ( 'Date Table'[Date].[Date]) )
)

         

    • AlB's avatar
      AlB
      Icon for Community Champion rankCommunity Champion
      7 years ago

      Hi v-lili6-msft

      Have you heard anything about this?

      Thanks

      • v-lili6-msft's avatar
        v-lili6-msft
        Icon for Community Support rankCommunity Support
        7 years ago

        hi, AlB

        Unfortunately, So far I haven't got any reply about this question.

        and I read these in the book The Definitive Guide to DAX: Business intelligence with Microsoft Excel, SQL Server Analysis Services, and Power BI by Marco Russo and Alberto Ferrari.

        in page 173:

         The following two definitions of PY YTD Sales are equivalent, even if the second one could be slightly faster (but barely measureable).

         

         

        and in your case, date table is from "2018,1,1" to today, you may try this formula

        Date Table = ADDCOLUMNS (
CALENDAR (DATE(2018,1,1), DATE(YEAR(TODAY()),12,31)),
"Year", YEAR ( [Date]),
"Month Name", FORMAT ( [Date], "mmmm" ),
"Monthnumber", FORMAT ( [Date], "MM" )
    )

         add a judge column for date table

        judge = IF('Date Table'[Date]<=TODAY(),1,2)

        Then add it to report level filter and set it "1"

         

        Result:

         

        This is just as a reference, I also think reason for this case is that date table is incomplete.

         

        Best Regards,

        Lin