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PBSuper's avatar
PBSuper
Frequent Visitor
9 years ago

MTD Previous

I am using SAMEPERIODLASTYEAR for my MTD Last Year calculation, however it returns Sales for the entire month of the previous year. So if I am reporting MTD sales for 17-08-2017, the MTD Last Year I ...
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TheOckieMofo's avatar
TheOckieMofo
Resolver II
9 years ago

Two things.

 

First, from a DAX perspective, I believe the formula you want is DATEADD. DateAdd will return partial periods whereas other functions return whole periods. Check this blog post for a good explanation: DateAdd

 

Second, a best practice I always use is to have a "trimmed" dates table, meaning I don't have dates that go beyond where I have data in my fact table. For example, I do a lot of month end reporting, so I always trim my dates table to stop at the last day of the prior month. The great thing about Power Query/M Language is that you can code this to basically be automatic.

 

So for your example, you would start by hardcoding that you want the date to be less than or equal to today's date. Once you do this, it will add a step to the query and you will see the M formula in the formula bar showing you what it's doing. Then, you can erase the hardcoded date in that formula bar and replace it with:

 

<=Date.From(DateTime.LocalNow())

 

This way, every time you refresh the data, your calendar table will always stop at todays date. There's a ton of date functions in M, so check out the Formula reference if there's other manipulations you need to make.

PBSuper's avatar
PBSuper
Frequent Visitor
9 years ago

I have already trimmed my calendar dimension in my tabular to not include any future dates. My fact is not going to have future sales so I probably don't have to worry about that. Doing this has not fixed my problem.

  • TomMartens's avatar
    TomMartens
    Super User
    9 years ago

    Hey,

     

    to answer similar questions I always use the following approach, maybe it seems a little complex, but I appreciate the degree of freedom it provides, the following measures uses the same number of dates in the previous month, for reasons of simplicity I skipped the treatment being on March 30 or March 31

     

    SameNumberOfPeriodsPrevMonth = 
var currentDay = DAY(MAXX(VALUES('Calendar'[Date]),'Calendar'[Date]))
var currentMonth = MONTH(MAXX(VALUES('Calendar'[Date]),'Calendar'[Date]))
var currentYear = YEAR(MAXX(VALUES('Calendar'[Date]),'Calendar'[Date]))
var startday = 1
var endday = currentDay
var startmonth = if(currentMonth = 1, 12, currentMonth-1)
var endmonth = if(currentMonth = 1, 12, currentMonth-1)
var startyear = if(currentMonth = 1, currentYear - 1, currentYear)
var endyear = if(currentMonth = 1, currentYear - 1, currentYear)
var startdate = DATE(startyear, startmonth, startday)
var endDate = DATE(endyear, endmonth, endday)
return
IF(NOT(ISBLANK(CALCULATE(SUM('FactWithDates'[Amount]))))
,CALCULATE(
	SUM('FactWithDates'[Amount])
	,DATESBETWEEN('Calendar'[Date], startdate, endDate)
)
,BLANK()
)

    The measure creates this output

     

    Hope this helps

     

    Regards

    • Hindska's avatar
      Hindska
      New Member
      5 years ago

      Worked like a charm. Dank u Tom! 🙂

  • v-jiascu-msft's avatar
    v-jiascu-msft
    Microsoft Employee
    9 years ago

    Hi PBSuper,

     

    Maybe it's something about context. Which table is the column date of the report from? Is it from table "Calendar"?

    This formula works fine in my test:

     

    TotalMTDLastYear =
TOTALMTD ( SUM ( Sales[Quantity] ), SAMEPERIODLASTYEAR ( 'Calendar'[Date] ) )

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

    Best Regards!

    Dale