PHP Weeknumber and start date and end date - php

Question

I am writing a program code to display the week-number between two dates. I als0 want to display the dates between the week-number. I have written the following code as per the example codes from stack overflow.(here && here)
function getStartAndEndDate($week, $year)
{
$time = strtotime("1 January $year", time());
$day = date('w', $time);
$time += ((7*$week)+1-$day)*24*3600;
$return[0] = date('dMY', $time);
$time += 6*24*3600;
$return[1] = date('dMY', $time);
return $return;
}
$startTime = strtotime('2013-04-01');
$endTime = strtotime('2013-05-03');
$weeks = array();
while ($startTime < $endTime)
{
$weeks[] = date('W', $startTime);
$startTime += strtotime('+1 week', 0);
}
echo count($weeks)."<br/>";
$year="2013";
foreach ($weeks as $key => $w)
{
echo "Week Number:".$w."--";
$return=getStartAndEndDate($w,$year);
$r0=$return[0];
$r1=$return[1];
echo "Start-".$r0."-End-".$r1."<br/>";
}
But the output is wrong. Output shows:
5
Week Number:14--Start-07Apr2013-End-13Apr2013
Week Number:14--Start-07Apr2013-End-13Apr2013
Week Number:15--Start-14Apr2013-End-20Apr2013
Week Number:16--Start-21Apr2013-End-27Apr2013
Week Number:17--Start-28Apr2013-End-04May2013
14th week starts from 31Mar2013 to 6Apr2013. I couldn't figure out what the problem is. Any help must be appreciated!

Answer 1

Did you try to check with date
$startTime = strtotime('2012-12-30');
$endTime = strtotime('2013-05-03');
The actual14th week is
Week Number:14--Start-08Apr2013-End-14Apr2013
not
14th week starts from 31Mar2013 to 6Apr2013
The PHP start weeks from Monday -->Sunday. So if you take 2012-12-30 which is Sunday it will calculate
Week Number:01--Start-07Jan2013-End-13Jan2013
Week Number:02--Start-14Jan2013-End-20Jan2013
Week Number:03--Start-21Jan2013-End-27Jan2013
Week Number:04--Start-28Jan2013-End-03Feb2013
Week Number:05--Start-04Feb2013-End-10Feb2013
Week Number:06--Start-11Feb2013-End-17Feb2013
Week Number:07--Start-18Feb2013-End-24Feb2013
Week Number:08--Start-25Feb2013-End-03Mar2013
Week Number:09--Start-04Mar2013-End-10Mar2013
Week Number:10--Start-11Mar2013-End-17Mar2013
Week Number:11--Start-18Mar2013-End-24Mar2013
Week Number:12--Start-25Mar2013-End-31Mar2013
Week Number:13--Start-01Apr2013-End-07Apr2013
Week Number:14--Start-08Apr2013-End-14Apr2013

Answer 2

I have figured it out:
function week_start_date($wk_num, $yr, $first = 1, $format = 'F d, Y')
{
$wk_ts = strtotime('+' . $wk_num . ' weeks', strtotime($yr . '0101'));
$mon_ts = strtotime('-' . date('w', $wk_ts) + $first . ' days', $wk_ts);
return date($format, $mon_ts);
}
$year="2013";
$startDate="2012-12-30";
$endDate="2013-05-03";
$p = new DatePeriod(
new DateTime($startDate),
new DateInterval('P1W'),
new DateTime($endDate)
);
foreach ($p as $k=>$w) {
echo $k.":".$w->format('W')."<br/>";
$w=$w->format('W');
$sStartDate = week_start_date($w, $year);
$sEndDate = date('F d, Y', strtotime('+6 days', strtotime($sStartDate)));
echo $sStartDate."&&".$sEndDate."<br/>";
}