Custom Year-Over-Year Calculation in DAX

This article describes how to implement a custom year-over-year calculation in DAX based on arbitrary associations between different periods. As an example, we describe the comparison of the 53rd week in a ISO Calendar. In the Week-Based Time Intelligence in DAX article, I described how to implement time intelligence calculations in DAX that works on ISO calendars. This approach offers a simplified way to implement custom time related calculations in DAX, as shown in the Time Patterns article on DAX Patterns web site.