Microsoft Power BI Data Analyst Practice Question

Time-intelligence functions work only against a dedicated date table that contains one row per day and spans a continuous range of dates. The expression that uses CALENDAR together with MIN and MAX from SensorReadings creates such a contiguous date table covering exactly the range present in the fact data. Once marked as a date table, it supports all built-in time-intelligence calculations and links to fact tables through a single relationship. Adding a calculated column inside SensorReadings leaves the model without a true date dimension and can create relationship ambiguity. Building a table with DISTINCT or SELECTCOLUMNS risks skipping days with no readings, breaking the continuity requirement. CALENDARAUTO generates a proper calendar but may include additional years from other tables, so it does not guarantee that the slicer shows only dates from SensorReadings.