getTimeFromNTPServer - PHP

function_getTimeFromNTPServer.php

<?php
/**
 * This function is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This Software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this function; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 **/

/**
 *
 * Connect to a timeserver and return formatted timestring.
 *
 * @param    string  $server The timeserver to query
 * @param    string  $dateformat The dateformat for returning the time
 * @return   string
 *
 */
function getTimeFromNTPServer($server='0.de.pool.ntp.org',$dateformat="Y-m-d H:i:s")
{
    $_adjustment = 0;
    $_data =null;

    $_fp = fsockopen($server, 37, $_errno, $_errstr, 30);

    if (!$_fp)
    {
        die( "$server: $_errstr ($_errno)");
    }
    else
    {

        while (!feof($_fp))
        {
            $_data .= fgets($_fp, 128);
        }

        fclose($_fp);

        if (strlen($_data) != 4)
        {
            die("NTP Server {$server} gab ungueltige Antwort zurueck.");
        }
    }

    $_ntpTime = ord($_data{0})*pow(256, 3) + ord($_data{1})*pow(256, 2) + ord($_data{2})*256 + ord($_data{3});

    $_from1990 = $_ntpTime - 2840140800;
    $_timeNow = $_from1990 + 631152000;

    $_time = date($dateformat, $_timeNow + $_adjustment);

    return $_time;
}