php 获取指定日期下个月的第一天和最后一天

function getNextMonth($date)
{//获取指定日期下个月的第一天和最后一天
    $arr = getdate();
    if ($arr['mon'] == 12) {
        $year = $arr['year'] + 1;
        $month = $arr['mon'] - 11;
        $day = $arr['mday'];
        if ($day < 10) {
            $mday = '0' . $day;
        } else {
            $mday = $day;
        }
        $firstday = $year . '-0' . $month . '-01';
        $lastday = $year . '-0' . $month . '-' . $mday;
    } else {
        $time = strtotime($date);
        $firstday = date('Y-m-01', strtotime(date('Y', $time) . '-' . (date('m', $time) + 1) . '-01'));
        $lastday = date('Y-m-d', strtotime("$firstday +1 month -1 day"));
    }
    $array = array('sdate' => $firstday, 'edate' => $lastday);
    return $array;
}