Day of week

Numeric representation of the day of the week. MySQL, Excel or PHP approaches to specify these date time.

Weekday

The value of weekday obtained from different approaches.

Weekday values from different approaches	Sunday	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday
PHP date with N format character: Weekday (ISO-8601)	7	1	2	3	4	5	6
MySQL WEEKDAY() function	6	0	1	2	3	4	5
MySQL DAYOFWEEK() Function	1	2	3	4	5	6	7
Excel WEEKDAY() function	1	2	3	4	5	6	7
PHP date with w format character	0	1	2	3	4	5	6

Get the date

Get the date of weekday from another known date (today or another specific day)

Day	Sunday	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday
Last week	MySQL: SELECT CURDATE() + INTERVAL -8 - WEEKDAY(CURDATE()) DAY; Excel: =TODAY()-WEEKDAY(NOW())-6 PHP: echo date('Y-m-d', strtotime("Sunday -14 day")) . PHP_EOL;	MySQL: SELECT CURDATE() + INTERVAL -7 - WEEKDAY(CURDATE()) DAY; Excel: =TODAY()-WEEKDAY(NOW())-5 PHP: echo date('Y-m-d', strtotime("monday this week -7 day")) . PHP_EOL;				PHP: echo date('Y-m-d', strtotime('Friday -7 day')) . PHP_EOL;	MySQL: SELECT CURDATE() + INTERVAL -2 - WEEKDAY(CURDATE()) DAY; PHP: (1) echo date('Y-m-d', strtotime("last Saturday")) . PHP_EOL; (2) echo date('Y-m-d', strtotime('last Saturday', strtotime("2018-03-04 00:01:00"))) . PHP_EOL;
This week	MySQL: SELECT CURDATE() + INTERVAL -1 - WEEKDAY(CURDATE()) DAY; Excel: =TODAY()-WEEKDAY(NOW())+1 PHP: echo date('Y-m-d', strtotime("Sunday -7 day")) . PHP_EOL;	MySQL: SELECT CURDATE() + INTERVAL 0 - WEEKDAY(CURDATE()) DAY; Excel: =TODAY()-WEEKDAY(NOW())+2 PHP: echo date('Y-m-d', strtotime("monday this week")) . PHP_EOL;	MySQL: SELECT CURDATE() + INTERVAL 1 - WEEKDAY(CURDATE()) DAY; Excel: =TODAY()-WEEKDAY(NOW())+3	MySQL: SELECT CURDATE() + INTERVAL 2 - WEEKDAY(CURDATE()) DAY; Excel: =TODAY()-WEEKDAY(NOW())+4	MySQL: SELECT CURDATE() + INTERVAL 3 - WEEKDAY(CURDATE()) DAY; Excel: =TODAY()-WEEKDAY(NOW())+5	MySQL: SELECT CURDATE() + INTERVAL 4 - WEEKDAY(CURDATE()) DAY; Excel: =TODAY()-WEEKDAY(NOW())+6 PHP: echo date('Y-m-d', strtotime('Friday')) . PHP_EOL;	MySQL: SELECT CURDATE() + INTERVAL 5 - WEEKDAY(CURDATE()) DAY; Excel: =TODAY()-WEEKDAY(NOW())+7 PHP: echo date('Y-m-d', strtotime("Saturday")) . PHP_EOL;
Next week	MySQL: SELECT CURDATE() + INTERVAL 6 - WEEKDAY(CURDATE()) DAY; Excel: =TODAY()-WEEKDAY(NOW())+8 PHP: echo date('Y-m-d', strtotime("Sunday")) . PHP_EOL;	MySQL: SELECT CURDATE() + INTERVAL 7 - WEEKDAY(CURDATE()) DAY; Excel: =TODAY()-WEEKDAY(NOW())+9 PHP: (1) echo date('Y-m-d', strtotime("next monday")) . PHP_EOL; (2) echo date('Y-m-d', strtotime("monday this week +7 day")) . PHP_EOL;				PHP: echo date('Y-m-d', strtotime('Friday +7 day')) . PHP_EOL;

Further reading

• PHP date function: w character (0 for Sunday through 6 for Saturday) or N character (1 for Monday through 7 for Sunday)
• WEEKDAY 函數 - Office 支援
• ISO 8601 - Wikipedia
• mysql - How to get this coming Sunday's date? - Stack Overflow
• 如何在 Excel 中傳回的日期星期幾
• TODAY 函數 - Office 支援