MySQL WEEK() function

MySQL WEEK() returns the week number for a given date.
The argument allows the user to specify whether the week starts on Sunday or Monday and whether the return value should be in the range from 0 to 53 or from 1 to 53. If no argument is included with the function, it returns the default week format.
Syntax :

WEEK(date[,mode]);

Arguments :

Name	Description
date	A date value.
mode	An integer indicating the starting of the week.

The following table describes how the mode arguments work :

Mode	First day of week	Range	Week 1 is the first week …
0	Sunday	0-53	with a Sunday in this year
1	Monday	0-53	with more than 3 days this year
2	Sunday	1-53	with a Sunday in this year
3	Monday	1-53	with more than 3 days this year
4	Sunday	0-53	with more than 3 days this year
5	Monday	0-53	with a Monday in this year
6	Sunday	1-53	with more than 3 days this year
7	Monday	1-53	with a Monday in this year