The DAYOFWEEK function returns a day in the range of 1 to 7 (1: Sunday, 2: Monday, ..., 7: Saturday) from the specified parameters. The day index is same as the ODBC standards. You can specify the DATE, TIMESTAMP, or DATETIME type; the value is returned in INTEGER type.
If every argument value of date and time is 0, the return value is determined by the return_null_on_function_errors system parameter; if it is set to yes, then NULL is returned; if it is set to no, an error is returned. The default value is no.
DAYOFWEEK(date)
SELECT DAYOFWEEK('2010-09-09');
dayofweek('2010-09-09')
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5
SELECT DAYOFWEEK('2010-09-09 19:49:29');
dayofweek('2010-09-09 19:49:29')
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5
SELECT DAYOFWEEK('10:28:00');
ERROR: Conversion error in date format.
SELECT DAYOFWEEK('0000-00-00');
ERROR: Conversion error in date format.