php 获取当天或某个日期是星期几

<?php
function getWeekName($data,$format = '星期')
{
    $week   =  date( "D ",$data);
    switch($week)
    {
        case "Mon ":
            $current   =   $format."一";
            break;
        case "Tue ":
            $current   =   $format."二";
            break;
        case "Wed ":
            $current   =   $format."三";
            break;
        case "Thu ":
            $current   =   $format."四";
            break;
        case "Fri ":
            $current   =   $format."五";
            break;
        case "Sat ":
            $current   =   $format."六";
            break;
        case "Sun ":
            $current   =   $format."日";
            break;
    }
    return $current;
}
 
echo '今天是：'.getWeekName(time(),'星期');
echo '<br>';
echo '今天是：'.getWeekName(time(),'礼拜');
echo '<br>';
echo '2010-12-12是：'.getWeekName(strtotime('2010-12-12'),'礼拜');
?>