Start day of the week based on year week number integer

[amalrio]

Hi all, 

I wanted to calculate a column in a tabel for week start date based on a year week number integer

as below..

YearWeek              Start Of the Week (new calculated column based on YearWeek column)

20211                    1/1/2021

20212                    4/1/2021

20213                    11/1/2021

....

....

202141                 6/9/2021

202142                 13/9/2021

is there any way I can do this. thanks for the help

@Anonymous 

[CNENFRNL · Accepted solution]

Simple enough with PQ,

let
    Source = List.TransformMany({2021,2022}, each {1..Date.WeekOfYear(#date(_,12,31), Day.Monday)}, (x,y) => {Text.From(x)&"-"&Number.ToText(y,"00"), List.Max({#date(x,1,1), Date.StartOfWeek(#date(x,1,1)+Duration.From((y-1)*7),Day.Monday)})}),
    #"Start of Week" = Table.FromRows(Source, {"yyyyww", "Start of Week"})
in
    #"Start of Week"

[VahidDM]

HI @amalrio 

It would be better to add a calendar table to your model and use that.

BTW, Try this code:

Column = 
Var _WN = FORMAT(right([YearWeek],LEN([YearWeek])-4),"####")
Var _MinYear = CALCULATE(left(min([YearWeek]),4),all('Table'))
Var _MaxYear = CALCULATE(left(Max([YearWeek]),4),all('Table'))
Var _Year = FORMAT(left([YearWeek],4),"####")
Var _DateT = filter(ADDCOLUMNS(calendar(Date(_MinYear,1,1),date(_MaxYear,12,31)),"Year",YEAR([Date]),"WeekN",WEEKNUM([Date]),"Day",format([Date],"ddd")),[Day]<>"Sat"&&[Day]<>"Sun")
Var _FirstDateWeek =ADDCOLUMNS(GROUPBY(_DateT,[WeekN],[Year],"Date",minx(CURRENTGROUP(),[Date])),"YW",CONCATENATE([Year],[WeekN]))
return
MAXX(filter(_FirstDateWeek,VALUE([YW])=[YearWeek]),[Date])

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Appreciate your Kudos!!