Obtain Dates from Weeknumber

Hey DevadathanK ,

I guess it's almost impossible without additional information like the year, or it is very much simplified. If you assume that week one starts always with the 1st of January.

For the latter you can use this DAX statement to create a calculated column that creates the startdate:

StartDate = 
var _year = 2020
return
DATE(_year , 1 , 1) + ('Table'[weeknum] - 1 ) * 7

and this to create a calculated column that represents the enddate:

EndDate = 
var _year = 2020
return
DATE(_year , 1 , 1) + ('Table'[weeknum] - 1 ) * 7 + 6

In addition, you can consider using a Date Table that is not related, this DAX creates a Date table for the year 2020:

Simple Date = 
var DateStart = DATE(2020 , 1 , 1)
var DateEnd = DATE(2020 , 12 , 31) 
return
ADDCOLUMNS(
    CALENDAR(DateStart , DateEnd)
    , "weeknum", WEEKNUM(''[Date] , 2) //week begins on Monday
    , "weeknum iso" , WEEKNUM(''[Date] , 21) //returns the weeknum based on ISO 8601
)

Now you can use this DAX Statement to find the starting date of the week in your existing table:

Startdate Calendar = 
var __Weeknum = 'Table'[weeknum]
return
CALCULATE(MIN('Simple Date'[Date]) ,  'Simple Date'[weeknum] = __Weeknum)

and this to find the enddate:

Enddate Calendar = 
var __Weeknum = 'Table'[weeknum]
return
CALCULATE(MAX('Simple Date'[Date]) ,  'Simple Date'[weeknum] = __Weeknum)

Here is a screenshot of the resulting table (the weeknum iso column can be used accordingly):

Hopefully, this provides what you are looking for.

Regards,
Tom