Microsoft Power BI Data Analyst Practice Question

The DATEADD function shifts every date in the current filter context by a specified interval and returns that shifted set of dates. Wrapping it in CALCULATE applies the shifted date table as a new filter, allowing Total Sales to be evaluated for the month exactly one month earlier than the selection while still honoring all other filters. SAMEPERIODLASTYEAR moves the context back an entire year, not one month. DATESINPERIOD creates a rolling-period window that counts back a number of days and can include part of the current month, so it does not guarantee the exact previous calendar month. PARALLELPERIOD with -12 months also returns the equivalent month a full year earlier, not simply the immediately prior month.