php毫秒转date

//毫秒转日期
function getMsecToMescdate($msectime)
{
    $msectime = $msectime * 0.001;
    if (strstr($msectime, '.')) {
        sprintf("%01.3f", $msectime);
        list($usec, $sec) = explode(".", $msectime);
        $sec = str_pad($sec, 3, "0", STR_PAD_RIGHT);
    } else {
        $usec = $msectime;
    }
    $date = date("Y-m-d H:i:s", $usec);
    return  $date;
}