问PHP获取月份的周数

EN

<?php

    /**
     * Returns the amount of weeks into the month a date is
     * @param $date a YYYY-MM-DD formatted date
     * @param $rollover The day on which the week rolls over
     */
    function getWeeks($date, $rollover)
    {
        $cut = substr($date, 0, 8);
        $daylen = 86400;

        $timestamp = strtotime($date);
        $first = strtotime($cut . "00");
        $elapsed = ($timestamp - $first) / $daylen;

        $weeks = 1;

        for ($i = 1; $i <= $elapsed; $i++)
        {
            $dayfind = $cut . (strlen($i) < 2 ? '0' . $i : $i);
            $daytimestamp = strtotime($dayfind);

            $day = strtolower(date("l", $daytimestamp));

            if($day == strtolower($rollover))  $weeks ++;
        }

        return $weeks;
    }


    //
    echo getWeeks("2011-06-11", "sunday"); //outputs 2, for the second week of the month
?>

function weekOfMonth($when = null) {
    if ($when === null) $when = time();
    $week = date('W', $when); // note that ISO weeks start on Monday
    $firstWeekOfMonth = date('W', strtotime(date('Y-m-01', $when)));
    return 1 + ($week < $firstWeekOfMonth ? $week : $week - $firstWeekOfMonth);
}

function weekOfMonth($when = null) {
    if ($when === null) $when = time();
    $week = strftime('%U', $when); // weeks start on Sunday
    $firstWeekOfMonth = strftime('%U', strtotime(date('Y-m-01', $when)));
    return 1 + ($week < $firstWeekOfMonth ? $week : $week - $firstWeekOfMonth);
}

public function getWeeks($timestamp)
{
    $maxday    = date("t",$timestamp);
    $thismonth = getdate($timestamp);
    $timeStamp = mktime(0,0,0,$thismonth['mon'],1,$thismonth['year']);    //Create time stamp of the first day from the give date.
    $startday  = date('w',$timeStamp);    //get first day of the given month
    $day = $thismonth['mday'];
    $weeks = 0;
    $week_num = 0;

    for ($i=0; $i<($maxday+$startday); $i++) {
        if(($i % 7) == 0){
            $weeks++;
        }
        if($day == ($i - $startday + 1)){
            $week_num = $weeks;
        }
      }     
    return $week_num;
}