Returns a number that represents the nth day of the week in which a date value falls.

Syntax

bigint weekday (datetime <date>)

Parameters

date: required. A value of the DATETIME type. The format is yyyy-mm-dd hh:mi:ss. If the input value is of the STRING type and the MaxCompute V1.0 data type edition is used in your project, the input value is implicitly converted into the DATETIME type before calculation.

Return value

A value of the BIGINT type is returned. The return value varies based on the following rules:
  • Monday is considered the first day of the week and its return value is 0. Days of the week are numbered in ascending order starting from 0. The return value of Sunday is 6.
  • If the value of date is not of the DATETIME or STRING type or the format does not meet the requirements, an error is returned.
  • If the value of date is null, null is returned.

Sample data

This section provides sample source data for you to understand how to use date functions. In this topic, a table named mf_date_fun_t is created and data is inserted into the table. Sample statements: 
create table if not exists mf_date_fun_t(
    id      int,
    date1   date,
    datetime1   datetime,
    timestamp1 timestamp,
    date2   date,
    datetime2   datetime,
    timestamp2 timestamp,
    date3 string,
    date4 bigint);
insert into mf_date_fun_t values
(1,DATE'2021-11-29',DATETIME'2021-11-29 00:01:00',TIMESTAMP'2021-01-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-20',123456780),
(2,DATE'2021-11-28',DATETIME'2021-11-28 00:02:00',TIMESTAMP'2021-02-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-21',123456781),
(3,DATE'2021-11-27',DATETIME'2021-11-27 00:03:00',TIMESTAMP'2021-03-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-22',123456782),
(4,DATE'2021-11-26',DATETIME'2021-11-26 00:04:00',TIMESTAMP'2021-04-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-23',123456783),
(5,DATE'2021-11-25',DATETIME'2021-11-25 00:05:00',TIMESTAMP'2021-05-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-24',123456784),
(6,DATE'2021-11-24',DATETIME'2021-11-24 00:06:00',TIMESTAMP'2021-06-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-25',123456785),
(7,DATE'2021-11-23',DATETIME'2021-11-23 00:07:00',TIMESTAMP'2021-07-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-26',123456786),
(8,DATE'2021-11-22',DATETIME'2021-11-22 00:08:00',TIMESTAMP'2021-08-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-27',123456787),
(9,DATE'2021-11-21',DATETIME'2021-11-21 00:09:00',TIMESTAMP'2021-09-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-28',123456788),
(10,DATE'2021-11-20',DATETIME'2021-11-20 00:10:00',TIMESTAMP'2021-10-11 00:00:00.123456789',DATE'2021-10-29',DATETIME'2021-10-29 00:00:00',TIMESTAMP'2021-10-11 00:00:00.123456789','2021-11-29',123456789);
Query data from the mf_date_fun_t table. Sample statement:
select * from mf_date_fun_t;
-- The following result is returned: 
+------------+------------+---------------------+-------------------------+------------+---------------------+-------------------------+------------+------------+
| id         | date1      | datetime1           | timestamp1              | date2      | datetime2           | timestamp2              | date3      | date4      |
+------------+------------+---------------------+-------------------------+------------+---------------------+-------------------------+------------+------------+
| 1          | 2021-11-29 | 2021-11-29 00:01:00 | 2021-01-11 00:00:00.123 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123 | 2021-11-20 | 123456780  |
| 2          | 2021-11-28 | 2021-11-28 00:02:00 | 2021-02-11 00:00:00.123 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123 | 2021-11-21 | 123456781  |
| 3          | 2021-11-27 | 2021-11-27 00:03:00 | 2021-03-11 00:00:00.123 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123 | 2021-11-22 | 123456782  |
| 4          | 2021-11-26 | 2021-11-26 00:04:00 | 2021-04-11 00:00:00.123 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123 | 2021-11-23 | 123456783  |
| 5          | 2021-11-25 | 2021-11-25 00:05:00 | 2021-05-11 00:00:00.123 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123 | 2021-11-24 | 123456784  |
| 6          | 2021-11-24 | 2021-11-24 00:06:00 | 2021-06-11 00:00:00.123 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123 | 2021-11-25 | 123456785  |
| 7          | 2021-11-23 | 2021-11-23 00:07:00 | 2021-07-11 00:00:00.123 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123 | 2021-11-26 | 123456786  |
| 8          | 2021-11-22 | 2021-11-22 00:08:00 | 2021-08-11 00:00:00.123 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123 | 2021-11-27 | 123456787  |
| 9          | 2021-11-21 | 2021-11-21 00:09:00 | 2021-09-11 00:00:00.123 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123 | 2021-11-28 | 123456788  |
| 10         | 2021-11-20 | 2021-11-20 00:10:00 | 2021-10-11 00:00:00.123 | 2021-10-29 | 2021-10-29 00:00:00 | 2021-10-11 00:00:00.123 | 2021-11-29 | 123456789  |
+------------+------------+---------------------+-------------------------+------------+---------------------+-------------------------+------------+------------+

Example: static data

-- The value 4 is returned. 
select weekday (datetime '2009-03-20 11:11:00');
-- The value 4 is returned. 
set odps.sql.type.system.odps2=false;
select weekday ('2009-03-20 11:11:00');
-- The value null is returned. 
select weekday (null);

Example: table data

Calculate the day of the week in which each date value in the datetime1 column falls. Data in Sample data is used in this example. Sample statement: 
select datetime1, weekday(datetime1) as datetime1_weekday from mf_date_fun_t;
The following result is returned: 
+---------------------+-------------------+
| datetime1           | datetime1_weekday |
+---------------------+-------------------+
| 2021-11-29 00:01:00 | 0                 |
| 2021-11-28 00:02:00 | 6                 |
| 2021-11-27 00:03:00 | 5                 |
| 2021-11-26 00:04:00 | 4                 |
| 2021-11-25 00:05:00 | 3                 |
| 2021-11-24 00:06:00 | 2                 |
| 2021-11-23 00:07:00 | 1                 |
| 2021-11-22 00:08:00 | 0                 |
| 2021-11-21 00:09:00 | 6                 |
| 2021-11-20 00:10:00 | 5                 |
+---------------------+-------------------+