SAMEPERIODLASTYEAR Function (DAX)
Returns a table that contains a column of dates shifted one year back in time from the dates in the specified dates column, in the current context.
To understand more about how context affects the results of formulas, see Context in DAX Formulas.
The dates argument can be any of the following:
A reference to a date/time column,
A table expression that returns a single column of date/time values,
A Boolean expression that defines a single-column table of date/time values.
Constraints on Boolean expressions are described in the topic, CALCULATE Function (DAX).
The dates returned are the same as the dates returned by this equivalent formula:
DATEADD(dates, -1, year)
The following sample formula creates a measure that calculates the previous year sales of the Reseller sales.
To see how this works, create a PivotTable and add the fields, CalendarYear to the Row Labels area of the PivotTable. Then add a measure, named Previous Year Sales, using the formula defined in the code section, to the Values area of the PivotTable.