WEEKDAY Function

Contents:

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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.

Wrangle vs. SQL: This function is part of Wrangle , a proprietary data transformation language. Wrangle is not SQL. For more information, see Wrangle Language.

Basic Usage

Column reference example:

weekday(MyDate)

Output: Returns the numeric weekday values derived from the MyDate column.

Syntax and Arguments

weekday(datetime_col)

Argument	Required?	Data Type	Description
datetime_col	Y	datetime	Name 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 Type	Example Value
Yes	Datetime	`myDate`

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:

WEEKDAY - returns numeric value for the day of the week for source Datetime values. See WEEKDAY Function.
WEEKNUM - returns the numeric value for the week within the year for source Datetime values. See WEEKNUM Function.
DATEFORMAT - can be used to format Datetime values in many different ways. See DATEFORMAT Function.

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:

myDate	weekDayNum	weekDayNameFull	weekDayNameShort	weekNum
10/30/17	1	Monday	Mon	44
10/31/17	2	Tuesday	Tue	44
11/1/17	3	Wednesday	Wed	44
11/2/17	4	Thursday	Thu	44
11/3/17	5	Friday	Fri	44
11/4/17	6	Saturday	Sat	44
11/5/17	7	Sunday	Sun	45
11/6/17	1	Monday	Mon	45

See Also:

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