如何从星期数获取开始日期

Question

Getting week number this format :

$weeknumber = date('W', strtotime('10-02-2015'));

How to get starting date from this weeknumber.

Answer 1

Use this

you need to change like this strtotime('10-02-2015'))

$date_string = "2012-10-18";
$weeknumber =  date("W", strtotime($date_string));

//get the date from week number

isodate

$gendate = new DateTime();
$gendate->setISODate(2013,$weeknumber ,4); //year , week num , day
echo $gendate->format('d-m-Y'); //"prints"  26-12-2013

Answer 2

you can use this

  echo $weeknumber = date('W', strtotime('18-10-2012'));
  $gendate = new DateTime();
  $gendate->setISODate(2015,$weeknumber,4); //year , week num , day
  echo $gendate->format('d-m-Y'); //"prints" 

Answer 3

Don't mix strtotime() and date() functions with DateTime class. It can be simply done without them, and with only DateTime , like:

$date = new DateTime('10-02-2015');
$date->setISODate($date->format('o'), $date->format('W'));
echo $date->format('d-m-Y');

demo