Previous X number of weeks from any selected date?

[Anonymous]

At the moment I have a matrix showing weekly sales values. I want to be able to select any particular date and then have the table filter the previous X amount of weeks' data prior to that selected date. In my date table I have week of the year (1-53) and also 'absolute' week of the year (i.e. 1 is the beginning of recorded data, 6xx is the current) - not sure if I can do anything with either of those. Be grateful for some advice, thank you.

[amitchandak · Accepted solution]

@Anonymous , with help from week rank column in a separate date/week table

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

You can measure like

This Week = CALCULATE(sum('Table'[Qty]), FILTER(ALL('Date'),'Date'[Week Rank]=max('Date'[Week Rank])))
Last Week = CALCULATE(sum('Table'[Qty]), FILTER(ALL('Date'),'Date'[Week Rank]=max('Date'[Week Rank])-1))

Last year Week= CALCULATE(sum('Table'[Qty]), FILTER(ALL('Date'),'Date'[Week Rank]=(max('Date'[Week Rank]) -52)))

Last 8 weeks = CALCULATE(sum('Table'[Qty]), FILTER(ALL('Date'),'Date'[Week Rank]>=max('Date'[Week Rank])-8 && 'Date'[Week Rank]<=max('Date'[Week Rank])))

or

This week = CALCULATE(sum('Table'[Qty]), FILTER(ALL('Date'),'Date'[Year]=max('Date'[Year]) && 'Date'[Week] = Max('Date'[Week]) ))

Last year same week = CALCULATE(sum('Table'[Qty]), FILTER(ALL('Date'),'Date'[Year]=max('Date'[Year])-1 && 'Date'[Week] = Max('Date'[Week])))

Power BI — Week on Week and WTD
https://medium.com/@amitchandak.1978/power-bi-wtd-questions-time-intelligence-4-5-98c30fab69d3
https://community.powerbi.com/t5/Community-Blog/Week-Is-Not-So-Weak-WTD-Last-WTD-and-This-Week-vs-Last-Week/ba-p/1051123
https://www.youtube.com/watch?v=pnAesWxYgJ8