Php A non well formed numeric value encountered

Question

From this code:

$kw = CalenderWeekHelper::getCalenderWeek($currentYear);
if(isset($_POST['generate'])) {
    for($i = 0; $i < 52; $i++) {
        foreach($users as $user) {

            if ($i > 52) {
                break;
            }
            $start = $kw[$i]['start'];
            $end   = $kw[$i]['end'];

            $startCon = date('Y-m-d', $start);
            $endCon   = date('Y-m-d', $end);
        }
    }
}

Helper Class:

class CalenderWeekHelper {

    public static function getCalenderWeek($year)
    {
        for ($i=0; $i <= 52; $i++)
        {
            $week = sprintf('%02s', $i);
        $from = date("Y-m-d", strtotime("{$year}W{$week}")); # d.m.Y
            $to   = date("Y-m-d", strtotime("{$year}W{$week} +6 days"));
            $weekArray[$i] = array('start' => $from, 'end' => $to);

        }
        return $weekArray;
    }
}

I received:

Notice: A non well formed numeric value encountered in ... line:

Which points to these lines:

$startCon = date('Y-m-d', $start);
$endCon   = date('Y-m-d', $end);

EDIT: var_dump($kw) prints out following:

array (size=53)

      0 => 
        array (size=2)
          'start' => string '1970-01-01' (length=10)
          'end' => string '1970-01-01' (length=10)
      1 => 
        array (size=2)
          'start' => string '2014-12-29' (length=10)
          'end' => string '2015-01-04' (length=10)
      2 => 
        array (size=2)
          'start' => string '2015-01-05' (length=10)
          'end' => string '2015-01-11' (length=10)
      3 => 
        array (size=2)
          'start' => string '2015-01-12' (length=10)
          'end' => string '2015-01-18' (length=10)
      4 => 
        array (size=2)
          'start' => string '2015-01-19' (length=10)
          'end' => string '2015-01-25' (length=10)
      5 => 
        array (size=2)
          'start' => string '2015-01-26' (length=10)
          'end' => string '2015-02-01' (length=10)
      6 => 
        array (size=2)
          'start' => string '2015-02-02' (length=10)
          'end' => string '2015-02-08' (length=10)
      7 => 
        array (size=2)
          'start' => string '2015-02-09' (length=10)
          'end' => string '2015-02-15' (length=10)
      8 => 
        array (size=2)
          'start' => string '2015-02-16' (length=10)
          'end' => string '2015-02-22' (length=10)
      9 => 
        array (size=2)
          'start' => string '2015-02-23' (length=10)
          'end' => string '2015-03-01' (length=10)
      10 => 
        array (size=2)
          'start' => string '2015-03-02' (length=10)
          'end' => string '2015-03-08' (length=10)
      11 => 
        array (size=2)
          'start' => string '2015-03-09' (length=10)
          'end' => string '2015-03-15' (length=10)
      12 => 
        array (size=2)
          'start' => string '2015-03-16' (length=10)
      'end' => string '2015-03-22' (length=10)

Does anyone know a solution?

Answer 1

The date() function only accepts a unix timestamp.

In your code, you have two options:

1: Use $start and $end directly, as they are already well formatted:

$startCon = $start;
$endCon = $end;

2: Turn $start and $end into a unix timestamp with strtotime():

$startCon = date('Y-m-d', strtotime($start));
$endCon   = date('Y-m-d', strtotime($end));

If you want to change the format, use the second one. If not, use the first.