根据年份以及周数来获取该周的周日到周六的日期(周日为一个星期的第一天)

function getWeekDate($year,$weeknum){
  $firstdayofyear=mktime(0,0,0,1,2,$year);
  $firstweekday=date('w',$firstdayofyear);
  $firstweenum=date('W',$firstdayofyear);
  if($firstweenum==1){
      $day=(1-($firstweekday-1))+7*($weeknum-1);
      $sun=date('Y-m-d',mktime(0,0,0,1,$day,$year));
      $mon=date('Y-m-d',mktime(0,0,0,1,$day+1,$year));
      $tues=date('Y-m-d',mktime(0,0,0,1,$day+2,$year));
      $wed=date('Y-m-d',mktime(0,0,0,1,$day+3,$year));
      $thurs=date('Y-m-d',mktime(0,0,0,1,$day+4,$year));
      $fri=date('Y-m-d',mktime(0,0,0,1,$day+5,$year));
      $sat=date('Y-m-d',mktime(0,0,0,1,$day+6,$year));
  }else{
      $day=(9-$firstweekday)+7*($weeknum-1);
      $sun=date('Y-m-d',mktime(0,0,0,1,$day,$year));
      $mon=date('Y-m-d',mktime(0,0,0,1,$day+1,$year));
      $tues=date('Y-m-d',mktime(0,0,0,1,$day+2,$year));
      $wed=date('Y-m-d',mktime(0,0,0,1,$day+3,$year));
      $thurs=date('Y-m-d',mktime(0,0,0,1,$day+4,$year));
      $fri=date('Y-m-d',mktime(0,0,0,1,$day+5,$year));
      $sat=date('Y-m-d',mktime(0,0,0,1,$day+6,$year));
  }

  return array($sun,$mon,$tues,$wed,$thurs,$fri,$sat);
}