Dynamic Week Number

[dwel0120]

I want to include the last 13 weeks of data in my charts from today's week. I first created a new column for 

Past13Weeks = IF(DATEDIFF([WEEKOF],TODAY(),DAY)<=91, 1, 0) but quickly realized that wouldn't work for year over year data, so now I am moving on to week number. Here are my columns SCHOOLYEAR, WEEKOF, WKNM, ect. 

[amitchandak]

@dwel0120 , do you have year and week number too,

Usually, we can create a rank on year week, A new column. But it should be in week/date column

New column Rank

Week Rank = RANKX(all('Date'),'Date'[Year Week],,ASC,Dense) //YYYYWW format

new  measures

Last 13 weeks = CALCULATE(sum('order'[Qty]), FILTER(ALL('Date'),'Date'[Week Rank]>=max('Date'[Week Rank])-13 && 'Date'[Week Rank]<=max('Date'[Week Rank])))
This Week = CALCULATE(sum('order'[Qty]), FILTER(ALL('Date'),'Date'[Week Rank]=max('Date'[Week Rank])))
Last Week = CALCULATE(sum('order'[Qty]), FILTER(ALL('Date'),'Date'[Week Rank]=max('Date'[Week Rank])-1))

[dwel0120]

@amitchandak The Week Rank is only giving me 1 for every row. 

Week Rank = RANKX(all('Table1'[WEEKOF]),'Table1'[WKNM],,ASC,Dense) //YYYYWW format

[amitchandak]

@dwel0120 , A new column

Week Rank = RANKX('Table1','Table1'[WKNM],,ASC,Dense) //YYYYWW format

prefer a separate week or date table 

refer if needed

https://www.youtube.com/watch?v=pnAesWxYgJ8