WEEKOFYEAR(date) returns the calendar week of the date as a number in the range from 1 to 53. : WEEKOFYEAR « Date Time Functions « MySQL Tutorial

1. MySQL Tutorial
2. Date Time Functions
3. WEEKOFYEAR

mysql>
mysql> SELECT WEEKOFYEAR('1998-02-20');
+--------------------------+
| WEEKOFYEAR('1998-02-20') |
+--------------------------+
|                        8 |
+--------------------------+
1 row in set (0.00 sec)