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 |
Tip: For additional examples, see Common Tasks.
Examples
Example - Day of Date functions
Functions:
| Item | Description |
|---|---|
| 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:
| 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 |
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