How to calculate YTD savings from the given table

[Anonymous]

Hello,

I am trying to calculate the YTD variance for my sample table shown below. 

Table Name is "Project Costs" 

I want to calculate YTD variance for this table

The formula is YTD variance = (Current month Variance) - (December month's variance of last year)

I used the below DAX calculation 

YTD_Variance = SUM('Project Costs'[Variance]) - CALCULATE(SUM('Project Costs'[Variance]), PREVIOUSMONTH('Date'[Date]))

This calculation works for January 2018 month, but for February 2018 it is showing wrong calculation as shown below.

Please help me correct DAX calculation 

PS: I have the date dimension included. 

Thanks

Bhavesh

[GilbertQ]

Hi there

Just for clarification you are looking for the second part of your DAX measure to look at the DEC of the Previous Year?

[Anonymous]

@GilbertQ yes, I think I need to change the second part of the DAX formula to get the DEC of the previous year. Any feedback and help is greatly appreciated, thanks 

[GilbertQ]

Hi @Anonymous

You can use this measure for your Dec Variance.

Dec Previous Year Variance = 
VAR TodaysDate =
    NOW ()
VAR PrevYear =
    YEAR ( TodaysDate ) - 1
VAR DecPreviousYearStart =
    DATE ( PrevYear, 12, 1 )
VAR DecPreviousYearEnd =
    DATE ( PrevYear, 12, 31 )
RETURN
    CALCULATE (
        SUM( 'Project Costs'[Variance] ),
        ALL ( 'Date' ),
        'Date'[Date] >= DecPreviousYearStart
            && 'Date'[Date] <= DecPreviousYearEnd
    )

Which you can then use for your final measure by referencing this measure above.