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NOTE:  Trifacta Wrangler is a free product with limitations on its features. Some features in the documentation do not apply to this product edition. See Product Limitations.

   

Derives the numeric value for the day of the week (1, 2, etc.). Input must be a reference to a column containing Datetime values.

NOTE: If the source Datetime value does not include a valid input for this function, a missing value is returned.

Tip: You can use the DATEFORMAT function to generate text versions of the day of the week. See Examples below.


Basic Usage

Column reference example:

derive type:single value:WEEKDAY(MyDate)

Output: Generates a column of values containing the numeric weekday values derived from the MyDate column.

Syntax and Arguments

derive type:single value:WEEKDAY(datetime_col)

ArgumentRequired?Data TypeDescription
datetime_colYdatetimeName of column whose weekday values are to be computed

For more information on syntax standards, see Language Documentation Syntax Notes.

datetime_col

Name of the column whose day-of-week value is to be computed.

  • Missing values for this function in the source data result in missing values in the output.
  • Multiple columns and wildcards are not supported.

Tip: You cannot insert constant Datetime values as inputs to this function. However, you can use the following: WEEKDAY(DATE(12,20,2017)).

Usage Notes:

Required?Data TypeExample Value
YesDatetimemyDate

Examples

Tip: For additional examples, see Common Tasks.

Example - Day of Date functions

This example illustrates how you can apply functions to derive day-of-week values out of a column of Datetime type.

Functions:

ItemDescription
WEEKDAY Function Derives the numeric value for the day of the week (1, 2, etc.). Input must be a reference to a column containing Datetime values.
WEEKNUM Function Derives the numeric value for the week within the year (1, 2, etc.). Input must be the output of the DATE function or a reference to a column containing Datetime values. The output of this function increments on Sunday.
DATEFORMAT Function Formats a specified Datetime set of values according to the specified date format. Source values can be a reference to a column containing Datetime values.

Source:

myDate
10/30/17
10/31/17
11/1/17
11/2/17
11/3/17
11/4/17
11/5/17
11/6/17


Transformation:

The following transformation step generates a numeric value for the day of week in a new column:

Transformation Name New formula
Parameter: Formula type Single row formula
Parameter: Formula WEEKDAY (myDate)
Parameter: New column name 'weekDayNum'

The following step generates a full text version of the name of the day of the week:

Transformation Name New formula
Parameter: Formula type Single row formula
Parameter: Formula DATEFORMAT(myDate, 'EEEE')
Parameter: New column name 'weekDayNameFull'

The following step generates a three-letter abbreviation for the name of the day of the week:

Transformation Name New formula
Parameter: Formula type Single row formula
Parameter: Formula DATEFORMAT(myDate, 'EEE')
Parameter: New column name 'weekDayNameShort'

The following step generates the numeric value of the week within the year:

Transformation Name New formula
Parameter: Formula type Single row formula
Parameter: Formula WEEKNUM (myDate)
Parameter: New column name 'weekNum'

Results:

myDateweekDayNumweekDayNameFullweekDayNameShortweekNum
10/30/171MondayMon44
10/31/172TuesdayTue44
11/1/173WednesdayWed44
11/2/174ThursdayThu44
11/3/175FridayFri44
11/4/176SaturdaySat44
11/5/177SundaySun45
11/6/171MondayMon45

See Also for EXAMPLE - Day of Functions:

See Also for WEEKDAY Function:

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