FIRSTDATE

Applies to: Calculated column Calculated table Measure Visual calculation

For date column input, returns the first date in the current context for the specified column of dates.

For calendar input, returns the first date in the current context based on the calendar.

Syntax

FIRSTDATE(<dates> or <calendar>)

Parameters

Return value

For date column input, a table containing a single column and single row with a date value.

For calendar input, a table that contains all primary tagged columns and all time related columns.

Remarks

• 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.

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

• For date column input, the Return value is a table that contains a single column and single value. Therefore, this function can be used as an argument to any function that requires a table in its arguments. Also, the returned value can be used whenever a date value is required.

• This function is not supported for use in DirectQuery mode when used in calculated columns or row-level security (RLS) rules.

Example

The following sample formula creates a measure that obtains the first date when a sale was made in the Internet sales channel for the current context.

= FIRSTDATE('InternetSales_USD'[SaleDateKey])

Example for calendar based time intelligence

The following sample formula creates a measure that obtains the first date when a sale was made in the Internet sales channel for the current context.

= FIRSTDATE(FiscalCalendar)

Related content

Date and time functions Time intelligence functions LASTDATE function FIRSTNONBLANK function