weeks in month

function weeksInMonth($year, $month, $sunday_first = false) {
    $format = ($sunday_first) ? 'w' : 'N';
    $date   = new DateTime();
    $first  = $date->setDate($year, $month, 1)->format($format) - 1 * (!$sunday_first);
    $days   = $date->format('t');

    return ceil(($days + $first) / 7);
}