$time = strtotime("2010.12.11");
$final = date("Y-m-d", strtotime("+1 month", $time));
$monthNum = 3;
$monthName = date('F', mktime(0, 0, 0, $monthNum, 10)); // March
$monthNum = 3;
$dateObj = DateTime::createFromFormat('!m', $monthNum);
$monthName = $dateObj->format('F'); // March