Explanation:
Box 1: Yes
To use DAX time-intelligence functions, the Dim_Date table must be marked as a date table in Power BI. This requires the table to have a column with a Date or DateTime data type, containing unique, non-null values, and spanning full years. Once marked, the Dim_Date table should be related to the Fact_Sales table, often using USERELATIONSHIP to manage multiple date columns like Order, Delivery, and Ship Dates.
Steps to Ensure Dim_Date Works for Time Intelligence:
Mark as Date Table: In Power BI Desktop, right-click Dim_Date in the Fields pane and select Mark as date table.
Select Date Column: Choose the specific column in Dim_Date that contains only unique date values.
Verify Requirements: Ensure the column has no nulls and contains contiguous dates.
Handle Multiple Relationships: For OrderDateKey, DeliveryDateKey, and ShipDateKey, create active/inactive relationships, using USERELATIONSHIP in measures to calculate sales based on the desired date context.
Box 2: Yes
To enable the use of the DateKey field in a time hierarchy, you must Mark as Date Table in Power BI. This ensures the table, likely Dim_Date, is recognized for time intelligence. The table must contain a unique, non-null date column with continuous dates, and be marked to enable proper handling of hierarchies like Year, Quarter, Month, and Day.
Box 3: No
Reference:
https://learn.microsoft.com/en-us/power-bi/transform-model/desktop-date-tables
https://learn.microsoft.com/en-us/power-bi/transform-model/desktop-date-tables