Retrieve Time from NTP server via PHP

Question

I have an issue with a Virtual Machine (VMWare/Ubuntu) that is getting out of time sync. We decided that the best thing to do was to get the time directly from an NTP server so I started researching a script to do that but nothing works so far, that's why I decided to come here and see if someone can point me in the right direction.

To clarify, I'm looking for a way to connect to a Time Server via PHP to retrieve the time directly and reuse it on a timestamp that I need to generate not to sync the server.

Answer 1

Here's a complete working code:

<?php
error_reporting(E_ALL ^ E_NOTICE);
ini_set("display_errors", 1);

date_default_timezone_set("America/Argentina/Buenos_Aires");

/* Query a time server (C) 1999-09-29, Ralf D. Kloth (QRQ.software) <ralf at qrq.de> */
function query_time_server ($timeserver, $socket)
{
    $fp = fsockopen($timeserver,$socket,$err,$errstr,5);
        # parameters: server, socket, error code, error text, timeout
    if($fp)
    {
        fputs($fp, "\n");
        $timevalue = fread($fp, 49);
        fclose($fp); # close the connection
    }
    else
    {
        $timevalue = " ";
    }

    $ret = array();
    $ret[] = $timevalue;
    $ret[] = $err;     # error code
    $ret[] = $errstr;  # error text
    return($ret);
} # function query_time_server


$timeserver = "ntp.pads.ufrj.br";
$timercvd = query_time_server($timeserver, 37);

//if no error from query_time_server
if(!$timercvd[1])
{
    $timevalue = bin2hex($timercvd[0]);
    $timevalue = abs(HexDec('7fffffff') - HexDec($timevalue) - HexDec('7fffffff'));
    $tmestamp = $timevalue - 2208988800; # convert to UNIX epoch time stamp
    $datum = date("Y-m-d (D) H:i:s",$tmestamp - date("Z",$tmestamp)); /* incl time zone offset */
    $doy = (date("z",$tmestamp)+1);

    echo "Time check from time server ",$timeserver," : [<font color=\"red\">",$timevalue,"</font>]";
    echo " (seconds since 1900-01-01 00:00.00).<br>\n";
    echo "The current date and universal time is ",$datum," UTC. ";
    echo "It is day ",$doy," of this year.<br>\n";
    echo "The unix epoch time stamp is $tmestamp.<br>\n";


    echo date("d/m/Y H:i:s", $tmestamp);
}
else
{
    echo "Unfortunately, the time server $timeserver could not be reached at this time. ";
    echo "$timercvd[1] $timercvd[2].<br>\n";
}
?>

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