DATEADD Function (DAX)
Returns a table that contains a column of dates, shifted either forward or backward in time by the specified number of intervals from the dates 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).
If the number specified for number_of_intervals is positive, the dates in dates are moved forward in time; if the number is negative, the dates in dates are shifted back in time.
The interval parameter is an enumeration, not a set of strings; therefore values should not be enclosed in quotation marks. Also, the values: year, quarter, month, day should be spelled in full when using them.
The result table includes only dates that exist in the dates column.
The following formula calculates dates that are one year before the dates in the current context.