Date.DayOfWeekName

Date

Returns the name of the day of the week for the given date.

Examples on this page use shared sample tables. View them to understand the input data before reading the examples below.

Syntax

Date.DayOfWeekName(date as any, optional culture as nullable text) as nullable text

Parameters

NameTypeRequiredDescription
dateanyYesA date, datetime, or datetimezone value.
culturetextNoA culture code such as "en-US" or "fr-FR" that controls the language of the returned day name.

Return Value

textThe localized name of the day of the week (e.g., "Monday").

Remarks

Date.DayOfWeekName returns the full, localized name of the day of the week for a given date, datetime, or datetimezone value. When no culture is provided, the function uses the current locale of the host environment. Always specify culture explicitly (e.g., "en-US") in production queries to ensure consistent output regardless of where the query runs.

To get a short name (e.g., "Mon"), use Date.ToText with the format string "ddd" instead. If the input is null, the function returns null.

Date.DayOfWeekName returns the display name only — it does not return a number. If you need the numeric day-of-week (0 = Sunday, 1 = Monday, etc.) for sorting or comparisons, use Date.DayOfWeek instead. You can combine both: add a sort column using Date.DayOfWeek and a display column using Date.DayOfWeekName.

Examples

Example 1: Add day name column to Sales table

Table.AddColumn(
    Table.SelectColumns(
        Table.FirstN(Sales, 5),
        {"OrderID", "OrderDate"}
    ),
    "DayName", each Date.DayOfWeekName([OrderDate], "en-US"), type text
)
Result
OrderID
OrderDate
DayName
111/15/2024Monday
221/18/2024Thursday
332/1/2024Thursday
442/10/2024Saturday
553/5/2024Tuesday

Example 2: Return a day name in French

#table(
    type table [Date = date, DayNameFR = text],
    {{#date(2024, 3, 15), Date.DayOfWeekName(#date(2024, 3, 15), "fr-FR")}}
)
Result
Date
DayNameFR
13/15/2024vendredi

Example 3: Add both a sort key and a display name

Table.AddColumn(
    Table.AddColumn(
        Table.SelectColumns(Table.FirstN(Sales, 5), {"OrderID", "OrderDate"}),
        "DayOfWeekNum", each Date.DayOfWeek([OrderDate], Day.Monday), Int64.Type
    ),
    "DayOfWeekName", each Date.DayOfWeekName([OrderDate], "en-US"), type text
)
Result
OrderID
OrderDate
DayOfWeekNum
DayOfWeekName
111/15/20240Monday
221/18/20243Thursday
332/1/20243Thursday
442/10/20245Saturday
553/5/20241Tuesday

Compatibility

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