Sum Sales Group by date

Hi everyone, 

i have a problem with my dax formula:

I'll try to explain and sorry for my bad english.

I have to sum the sales of one month and compare with the same month of the previous year. the problem that i have at this moment is that when a data of the last year doesnt match with the same data of this year i have a blank resoult but i would like to have the same resoult of the previous day.

For Example: in for the date 16/04/2018 in the second coloumn instead of the blank value i would like to have 612997.66 the same of the previous day. the first value available. 

at this moment i use this dax formula:

Sales Last Year2 = CALCULATE(SUM(VENDITE[Valore]);DATESMTD(SAMEPERIODLASTYEAR(VENDITE[DATA_V])))

i tried to modify with this dax

Sales Last Year = IF(
            ISBLANK(CALCULATE(SUM(VENDITE[Valore]);DATESMTD(SAMEPERIODLASTYEAR(VENDITE[DATA_V])))
                );
            CALCULATE(SUM(VENDITE[Valore]);DATESMTD(SAMEPERIODLASTYEAR(VENDITE[DATA_V]-1))
                );
            CALCULATE(SUM(VENDITE[Valore]);DATESMTD(SAMEPERIODLASTYEAR(VENDITE[DATA_V])))
)

But the resoult is this:

i do not undestand where he takes 1.431.078.25.

Pls help me.

Thanks

Giovanni Morabito