Hello.
She did not long ago schedule one for weeks
I had raschityval in the selected period the first week and end
I did this so in PHP
$date_start = strtotime("2018-05-03"); // here can the transformation be different $week_start=date("W", $date_start);
That is, we get 18 a week for date 2018-05-03
Do inquiry in base of this type
SELECT `date_invoice` ,WEEK(date_invoice) as week_num FROM `invoce` WHERE `date_invoice` BETWEEN '2018-05-01' AND '2018-05-31'
And get 13 records with dates 2018-05-03 and 2018-05-04
I decided Preminet database for standard function WEEK as you can see from the query
But the problem is that php gives me the date 2018-05-03 - 18 week
but MySQL gives the date 2018-05-03 - 17 week
But in fact PHP is correctly believes
Here is an example of output from the database, for those who do not believe