WEEK()

Returns the week number for date. If passed the optional mode parameter, the week number returned will be modified according to Table D-3. You can also use the function WEEKOFYEAR, which is equivalent to using the WEEK function with a mode of 3. This code returns the week number 14:

SELECT WEEK('2016-04-04', 1);

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

Name