convert excel formula to powerbi function - calc start date from end date - duration (D/W/M/Y)

[mcraven1845]

I need to check the duration to determine if it is days/weeks/months/years and then do a different forumla to get the start date.  I can do this in excel but I don't know what reserve words work in power bi.  If you know of a better way to do this with some reserved function or formula or measure in power bi please share with me.  I will be so grateful.  thanks. Michelle

Here is the actual completed formula but I first have to split the duration into two columns separating out the number.  Also I made functions for each type.

=IF(VLOOKUP(E3,USEFRM,2,TRUE)="CALCDAY",CALCDAY(C3,D3),IF(VLOOKUP(E3,USEFRM,2,TRUE)="CALCWEEK",CALCWEEK(C3,D3),IF(VLOOKUP(E3,USEFRM,2,TRUE)="CALCMONTH",CALCMONTH(C3,D3),CALCYEAR(C3,D3))))

[v-yuta-msft]

@mcraven1845 ,

In DAX, LOOKUPVALUE() is similar to VLOOPUP(), in addtion, I haven't found any reference about CALCWEEK(), CALCMONTH() and CALCYEAR(), however, you may refer to the time intelligence functions here.

Community Support Team _ Jimmy Tao

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[mcraven1845 · Accepted solution]

Thank you for replying... I figure out a way first using the DAX side then I went back to the power query editor and created a function to add the new column with the desired results.  Going back and forth between syntax is keeping me on my toes.  

Below is the function I created that is working.

let StartUpgradeDate = (DurTime,DurCnt,UpgradeRpDate) => if DurTime="day" or DurTime="days" then
                                   Date.AddDays(UpgradeRpDate, (DurCnt*-1))
                           else if DurTime="week" or DurTime="weeks" then
                                   Date.AddWeeks(UpgradeRpDate, (DurCnt*-1))
                           else if DurTime="month" or DurTime="months" then
                                  Date.AddMonths(UpgradeRpDate, (DurCnt*-1))
                           else if DurTime="year" or DurTime="years" then
                                  Date.AddYears(UpgradeRpDate, (DurCnt*-1))
                           else ""
in StartUpgradeDate