How does the FIRSTDATE function (DAX) work?

The FIRSTDATE function (DAX) returns the first date in the current context for the specified column of dates.

FIRSTDATE Formula Syntax


How do you use the FIRSTDATE function?

The FIRSTDATE function can be used as a parameter to any DAX function that requires a table in its parameters. Further, the returned value can be used wherever a date value is required.

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Considerations when using the FIRSTDATE function

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.

When the current context is a single date, the date returned by the FIRSTDATE and LASTDATE functions will be equal.

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Formula examples using the FIRSTDATE function


= FIRSTDATE (Sales [Date])


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