Serverprom

function getDatesForThisAndNextWeek()
{
  $days = ['Monday' => 1, 'Tuesday' => 2, 'Wednesday' => 3, 'Thursday' => 4, 'Friday' => 5, 'Saturday' => 6, 'Sunday' => 7];

  $i = 1;
  foreach($days as $k => $v)
  {
    $today = new \DateTime();
    $today->setISODate((int)$today->format('o'), (int)$today->format('W'), $days[ ucfirst($k) ]);
    $daysArray[ $i ] = $today->format('Y-m-d');

    $todayPlusWeek       = $today->modify('+1 week');
    $daysArray[ $i + 7 ] = $todayPlusWeek->format('Y-m-d');

    $i++;
  }
  ksort($daysArray);
  return $daysArray;
}

var_dump(getDatesForThisAndNextWeek());