Source Code of jQuery plugin at https://github.com/Lwangaman/jQuery-Clock-Plugin >> Source Code of this example <<
Server: | 0.uk.pool.ntp.org |
VN (version number): | 3 |
Mode: | 4 |
Stratum: | 3 |
Origin time: | 1701913386.219 |
Received: | 1701913386.2207 |
Transmitted: | 1701913386.2208 |
Delay: | 2 ms |
NTP time: | 1701913386 |
NTP time formatted: | 2023-12-07 01:43:06 AM UTC .2192 |
NTP time adjusted to Europe/London timezone: | 1701913386 |
NTP time adjusted to Europe/London timezone formatted: | 2023-12-07 01:43:06 AM Europe/London |
NTP time adjusted to Europe/London timezone then adjusted to account for timezone offset: | 1701913386 |
NTP time adjusted to Europe/London timezone then adjusted to account for timezone offset, formatted: | 2023-12-07 01:43:06 AM Europe/London |
<?php
/* Query an NTP time server on port 123 (SNTP protocol) : */
$bit_max = 4294967296;
$epoch_convert = 2208988800;
$vn = 3;
$servers = array('0.uk.pool.ntp.org','1.uk.pool.ntp.org','2.uk.pool.ntp.org','3.uk.pool.ntp.org');
$server_count = count($servers);
//see rfc5905, page 20
//first byte
//LI (leap indicator), a 2-bit integer. 00 for 'no warning'
$header = '00';
//VN (version number), a 3-bit integer. 011 for version 3
$header .= sprintf('%03d',decbin($vn));
//Mode (association mode), a 3-bit integer. 011 for 'client'
$header .= '011';
//echo bindec($header);
//construct the packet header, byte 1
$request_packet = chr(bindec($header));
//we'll use a for loop to try additional servers should one fail to respond
$i = 0;
for($i; $i < $server_count; $i++) {
$socket = @fsockopen('udp://'.$servers[$i], 123, $err_no, $err_str,1);
if ($socket) {
//add nulls to position 11 (the transmit timestamp, later to be returned as originate)
//10 lots of 32 bits
for ($j=1; $j<40; $j++) {
$request_packet .= chr(0x0);
}
//the time our packet is sent from our server (returns a string in the form 'msec sec')
$local_sent_explode = explode(' ',microtime());
$local_sent = $local_sent_explode[1] + $local_sent_explode[0];
//add 70 years to convert unix to ntp epoch
$originate_seconds = $local_sent_explode[1] + $epoch_convert;
//convert the float given by microtime to a fraction of 32 bits
$originate_fractional = round($local_sent_explode[0] * $bit_max);
//pad fractional seconds to 32-bit length
$originate_fractional = sprintf('%010d',$originate_fractional);
//pack to big endian binary string
$packed_seconds = pack('N', $originate_seconds);
$packed_fractional = pack("N", $originate_fractional);
//add the packed transmit timestamp
$request_packet .= $packed_seconds;
$request_packet .= $packed_fractional;
if (fwrite($socket, $request_packet)) {
$data = NULL;
stream_set_timeout($socket, 1);
$response = fread($socket, 48);
//the time the response was received
$local_received = microtime(true);
//echo 'response was: '.strlen($response).$response;
}
fclose($socket);
if (strlen($response) == 48) {
//the response was of the right length, assume it's valid and break out of the loop
break;
}
else {
if ($i == $server_count-1) {
//this was the last server on the list, so give up
die('unable to establish a connection');
}
}
}
else {
if ($i == $server_count-1) {
//this was the last server on the list, so give up
die('unable to establish a connection');
}
}
}
//unpack the response to unsiged lonng for calculations
$unpack0 = unpack("N12", $response);
//print_r($unpack0);
//present as a decimal number
$remote_originate_seconds = sprintf('%u', $unpack0[7])-$epoch_convert;
$remote_received_seconds = sprintf('%u', $unpack0[9])-$epoch_convert;
$remote_transmitted_seconds = sprintf('%u', $unpack0[11])-$epoch_convert;
$remote_originate_fraction = sprintf('%u', $unpack0[8]) / $bit_max;
$remote_received_fraction = sprintf('%u', $unpack0[10]) / $bit_max;
$remote_transmitted_fraction = sprintf('%u', $unpack0[12]) / $bit_max;
$remote_originate = $remote_originate_seconds + $remote_originate_fraction;
$remote_received = $remote_received_seconds + $remote_received_fraction;
$remote_transmitted = $remote_transmitted_seconds + $remote_transmitted_fraction;
//unpack to ascii characters for the header response
$unpack1 = unpack("C12", $response);
//print_r($unpack1);
//echo 'byte 1: ' . $unpack1[1] . ' | ';
//the header response in binary (base 2)
$header_response = base_convert($unpack1[1], 10, 2);
//pad with zeros to 1 byte (8 bits)
$header_response = sprintf('%08d',$header_response);
//Mode (the last 3 bits of the first byte), converting to decimal for humans;
$mode_response = bindec(substr($header_response, -3));
//VN
$vn_response = bindec(substr($header_response, -6, 3));
//the header stratum response in binary (base 2)
$stratum_response = base_convert($unpack1[2], 10, 2);
$stratum_response = bindec($stratum_response);
//echo 'stratum: ' . bindec($stratum_response);
//calculations assume a symmetrical delay, fixed point would give more accuracy
$delay = (($local_received - $local_sent) / 2) - ($remote_transmitted - $remote_received);
$delay_ms = round($delay * 1000) . ' ms';
//echo 'delay: ' . $delay * 1000 . 'ms';
$server = $servers[$i];
$ntp_time = $remote_transmitted - $delay;
$ntp_time_explode = explode('.',$ntp_time);
$ntp_time_formatted = date('Y-m-d H:i:s A e ', $ntp_time_explode[0]).'.'.$ntp_time_explode[1];
//compare with the current server time
$server_time = microtime();
$server_time_explode = explode(' ', $server_time);
$server_time_micro = round($server_time_explode[0],4);
$server_time_formatted = date('Y-m-d H:i:s A e ', $server_time_explode[1]) .'.'. substr($server_time_micro,2);
//$server_time = time();
//$server_time_formatted = date('Y-m-d H:i:s', $server_time);
date_default_timezone_set('Europe/Rome');
$time = $ntp_time_explode[0];
$time_formatted = date('Y-m-d H:i:s A e', $time);
$time0 = $ntp_time_explode[0] - date('Z');
$time0_formatted = date('Y-m-d H:i:s A e', $time0);
//$time = microtime();
//$time_explode = explode(' ', $time);
//$time_micro = round($time_explode[0],4);
//$time_formatted = date('Y-m-d H:i:s A e', $time_explode[1]) .'.'. substr($time_micro,2);
/*
$time0 = time() - date('Z');
$time0_formatted = date('Y-m-d H:i:s A e', $time0); // 12:50:29
$time3 = date('h:i:s A e', gmdate('U')); // 14:50:29
$time4 = gmstrftime("%I:%M:%S %p %Z",time());
$timezone = "";
if (date_default_timezone_get()) {
$timezone = date_default_timezone_get();
}
elseif(ini_get('date.timezone')){
$timezone = ini_get('date.timezone');
}
*/
?>
<html>
<head>
<title>jQuery Clock NTP timestamp example</title>
<meta charset="UTF-8">
<style type="text/css">
html, body {height: 100%; margin: 0; padding: 0; background-color: Gray; }
#clocks-container { border: 1px groove White; border-radius: 15px; padding: 10px; width: 40%; float: left; margin: 30px; background-color: LightGray; text-align: center; }
#table-container { border: 1px solid Green; border-radius: 15px; padding: 10px; width: 40%; float: left; margin: 30px; background-color: White; text-align: center; }
#ntp-results-table { }
td{
width: 160px; height: 20px;
padding: 4px;
border: 1px solid #000;
font-size: 12px;
}
.ntp_response{
width: 240px;
}
/* SAMPLE CSS STYLES FOR JQUERY CLOCK PLUGIN */
.jqclock { text-align:center; border: 2px #369 ridge; background-color: #69B; padding: 10px; margin:20px auto; width: 40%; box-shadow: 5px 5px 15px #005; }
.clockdate { color: DarkRed; font-weight: bold; background-color: #8BD; margin-bottom: 10px; font-size: 18px; display: block; padding: 5px 0; text-shadow: 1px 1px 3px #FCC; outline: 1px solid White; }
.clocktime { border: 2px inset DarkBlue; outline: 3px ridge LightBlue; background-color: #444; padding: 5px 0; font-size: 14px; font-family: "Courier"; color: LightGreen; margin: 2px; display: block; font-weight:bold; text-shadow: 1px 1px 1px Black; }
.servertimetest { border: 1px solid Blue; margin: 2px; }
</style>
<script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script type="text/javascript" src="//rawgit.com/Lwangaman/jQuery-Clock-Plugin/master/jqClock.js"></script>
<script type="text/javascript">
$(document).ready(function(){
customtimestamp = parseInt($("#jqclock").data("time"));
console.log("current local timestamp is " + new Date().getTime());
console.log("current ntp timestamp is " + customtimestamp);
$("#jqclock").clock({"langSet":"en","timestamp":customtimestamp});
$("#jqclock-local").clock({"langSet":"en"});
});
</script>
</head>
<body>
<h1>jQuery Clock Server Example</h1>
<p><i>Source Code of jQuery plugin at <a href="https://github.com/Lwangaman/jQuery-Clock-Plugin">https://github.com/Lwangaman/jQuery-Clock-Plugin</a></i></p>
<div>
<div id="table-container">
<h2>NTP Server Request</h2>
<table id="ntp-results-table" border="0" align="center">
<tr>
<td>Server:
<td class="ntp_response"><?php echo $server;?></td>
</tr>
<tr>
<td>VN (version number):</td>
<td class="ntp_response"><?php echo $vn_response;?></td>
</tr>
<tr>
<td>Mode:</td>
<td class="ntp_response"><?php echo $mode_response;?></td>
</tr>
<tr>
<td>Stratum:</td>
<td class="ntp_response"><?php echo $stratum_response;?></td>
</tr>
<tr>
<td>Origin time:</td>
<td class="ntp_response"><?php echo $remote_originate;?></td>
</tr>
<tr>
<td>Received:</td>
<td class="ntp_response"><?php echo $remote_received;?></td>
</tr>
<tr>
<td>Transmitted:</td>
<td class="ntp_response"><?php echo $remote_transmitted;?></td>
</tr>
<tr>
<td>Delay:</td>
<td class="ntp_response"><?php echo $delay_ms;?></td>
</tr>
<tr>
<td>NTP time:</td>
<td class="ntp_response"><?php echo $ntp_time_explode[0];?></td>
</tr>
<tr>
<td>NTP time formatted:</td>
<td class="ntp_response"><?php echo $ntp_time_formatted;?></td>
</tr>
<tr>
<td>NTP time adjusted to Europe/London timezone:</td>
<td class="ntp_response"><?php echo $time;?></td>
</tr>
<tr>
<td>NTP time adjusted to Europe/Rome timezone formatted:</td>
<td class="ntp_response"><?php echo $time_formatted; ?></td>
</tr>
<tr>
<td>NTP time adjusted to Europe/London timezone then adjusted to account for timezone offset:</td>
<td class="ntp_response"><?php echo $time0;?></td>
</tr>
<tr>
<td>NTP time adjusted to Europe/Rome timezone then adjusted to account for timezone offset, formatted:</td>
<td class="ntp_response"><?php echo $time0_formatted; ?></td>
</tr>
<!--
<tr>
<td>Server time:</td>
<td class="ntp_response"><?php /* echo $server_time; */?></td>
</tr>
<tr>
<td>Server time formatted:</td>
<td class="ntp_response"><?php /*echo $server_time_formatted;*/?></td>
</tr>
<tr>
<td>Server time as London timezone:</td>
<td class="ntp_response"><?php /*echo $time;*/?></td>
</tr>
<tr>
<td>Server time as London timezone formatted:</td>
<td class="ntp_response"><?php /*echo $time_formatted;*/?></td>
</tr>
<tr>
<td>Server time as London timezone, stripped of timezone offset:</td>
<td class="ntp_response"><?php /*echo $time0;*/?></td>
</tr>
<tr>
<td>Server time as London timezone formatted, stripped of timezone offset:</td>
<td class="ntp_response"><?php /*echo $time0_formatted;*/?></td>
</tr>
-->
</table>
</div>
<div id="clocks-container">
<h2>Current NTP Time:</h2>
<div id="jqclock" data-time="<?php echo $time; ?>"></div>
<div id="jqclock-reference-date"><?php echo strftime("%A, %B %e, %Y",$time); ?></div>
<div class="servertimetest" id="jqclock-reference-time"><i>Time being fed into the jquery clock:</i> <br><?php echo $time_formatted; /* strftime("%I:%M:%S %p %Z",$time); */ ?></div>
<h2>Compared to Current Local Time:</h2>
<div id="jqclock-local"></div>
</div>
</div>
</body>
</html>