MariaDB DAYOFWEEK() Function

In MariaDB, DAYOFWEEK() is a built-in function that returns a number representing the weekday for a given date.

MariaDB DAYOFWEEK() Syntax

This is the syntax of the MariaDB DAYOFWEEK() function:

DAYOFWEEK(expr)

Parameters

expr

Required. A date or datetime expression.

If you provide no parameters or the wrong number of parameters, MariaDB will report an error: ERROR 1582 (42000): Incorrect parameter count in the call to native function 'DAYOFWEEK'.

Return value

The MariaDB DAYOFWEEK() function returns the index of the weekday for a given date. It returns a integer from 1 to 7, representing the following meanings:

  • 1- Sunday
  • 2- Monday
  • 3- Tuesday
  • 4- Wednesday
  • 5- Thursday
  • 6- Friday
  • 7- Saturday

If the specified expression is not a valid date or datetime, the DAYOFWEEK() function will return NULL.

If the argument is NULL, the DAYOFWEEK() function will return NULL.

MariaDB DAYOFWEEK() Examples

Basic usage

SELECT
    DAYOFWEEK('2022-02-21'),
    DAYOFWEEK('2022-02-22'),
    DAYOFWEEK('2022-02-23'),
    DAYOFWEEK('2022-02-24'),
    DAYOFWEEK('2022-02-25'),
    DAYOFWEEK('2022-02-26'),
    DAYOFWEEK('2022-02-27')\G

Output:

DAYOFWEEK('2022-02-21'): 2
DAYOFWEEK('2022-02-22'): 3
DAYOFWEEK('2022-02-23'): 4
DAYOFWEEK('2022-02-24'): 5
DAYOFWEEK('2022-02-25'): 6
DAYOFWEEK('2022-02-26'): 7
DAYOFWEEK('2022-02-27'): 1

Invalid date

If the specified expression is not a valid date or datetime, the DAYOFWEEK() function will return NULL.

SELECT
    DAYOFWEEK('2022-02-00'),
    DAYOFWEEK('2022-02-30'),
    DAYOFWEEK('Not A DATE')\G

Output:

DAYOFWEEK('2022-02-00'): NULL
DAYOFWEEK('2022-02-30'): NULL
DAYOFWEEK('Not A DATE'): NULL

Other delimiters

The MariaDB DAYOFWEEK() function allow you to construct dates with various separators:

SELECT
    DAYOFWEEK('2023/01/08'),
    DAYOFWEEK('2023,01!08'),
    DAYOFWEEK('2023#01%08');

Output:

+-------------------------+-------------------------+-------------------------+
| DAYOFWEEK('2023/01/08') | DAYOFWEEK('2023,01!08') | DAYOFWEEK('2023#01%08') |
+-------------------------+-------------------------+-------------------------+
|                       1 |                       1 |                       1 |
+-------------------------+-------------------------+-------------------------+

Conclusion

In MariaDB, DAYOFWEEK() is a built-in function that returns a number representing the weekday for a given date.