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AlB's avatar
AlB
Icon for Community Champion rankCommunity Champion
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.

     

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. 

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

     

     

     

     

     

     

     

     

     

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

      I would think that marcorusso might like to dig into this one. All I can say is this is the kind of reason that I creaed the Time Intelligence The Hard Way Quick Measure:

      https://community.powerbi.com/t5/Quick-Measures-Gallery/Time-Intelligence-quot-The-Hard-Way-quot-TITHW/m-p/434008

       

      The time intelligence functions are just these mysterious little black boxes that just act downright weird at times. I frankly don't really trust them as far as I can try catch throw them.

      • marcorusso's avatar
        marcorusso
        Icon for Most Valuable Professional rankMost Valuable Professional
        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.