Power BI Non Standard Calendar Previous Year

[Anonymous]

I am working with a floating fiscal year calendar.  Each period is 28 days; however if 12/31 falls on a saturday then this will count as a 53rd week otherwise.  it's only 52 weeks.   

Objective:

1. Make table B the same as Table A with the one year floating offset.
2. Allow the use of week, period, and year slicers within Power BI, while maintaining the integrity of the data regardless of which slicer and/or filters applied within the slicer. 

Background Info:

1. Not using an ISO date table
2. Not using a relative date table
3. Used End of Week from dates; then caculated weeks and periods off of End of Week. 

The function driving table B is DateAdd(Date(Datekey), -1, Year).  

Thank you for your assistance in advance.

[v-chuncz-msft · Accepted solution]

@Anonymous,

Try using CALCULATE Function to change the context.

• https://community.powerbi.com/t5/Desktop/Year-on-year-for-previous-reporting-period/m-p/326661#M1457...
• https://www.sqlbi.com/articles/filter-arguments-in-calculate/