Codeigniter time ago function

function time_ago($ptime) {
    $today = time();
    $createdday = strtotime('2018-09-09 23:08:42');
    $today_d = new DateTime();
    $today_d->setTimestamp($today);
    $createdday_d = new DateTime();
    $createdday_d->setTimestamp($createdday);
    $datediff = abs($today - $createdday);
    $difftext = '';

    $years = floor($datediff / (365 * 60 * 60 * 24));
    $datediff -= $years * (365 * 60 * 60 * 24);

    $months = floor($datediff / (30 * 60 * 60 * 24));
    $datediff -= $months * (30 * 60 * 60 * 24);

    $days = floor($datediff / (60 * 60 * 24));
    $datediff -= $days * (60 * 60 * 24);

    $hours = floor($datediff / 3600);
    $datediff -= $hours * 3600;

    $minutes = floor($datediff / 60);
    $datediff -= $minutes * 60;

    $seconds = floor($datediff);
    print_r(compact('years', 'months','days','hours','minutes','seconds'));
  }


//Outputs while the time was '2018-09-09 23:47'
Array ( [years] => 0 [months] => 0 [days] => 0 [hours] => 0 [minutes] => 21 [seconds] => 52 )