pandorafms/pandora_console/include/help/en/help_timesource.php

<?php
/**
 * @package Include/help/en
 */
?>
<h1>Time Source</h1>

<p>
What source to use for the time. This can be (for now) either the local system (System) or database (Database).<br />
</p>
<p>
This is useful when your database is not on the same system as your webserver or your <?php echo get_product_name(); ?> servers. 
In that case any time difference will miscalculate the time differences and timestamps.
You should use NTP to sync all your <?php echo get_product_name(); ?> servers and your MySQL server. 
By using these preferences you don't have to sync your webserver but it's still recommended.
</p>
<p>
Feel free to implement more sources (eg: ntp, ldap, $_SERVER...).
</p>
<p>
Note: The database query will be cached the first time it's called so the time will always be the same on a page load throughout, while System time is returned whenever the function is called, which might differ slightly (especially near the ending of a second).
</p>
<p>
These examples are all returning Unixtime
<script type="text/javascript">
var date = new Date; // Generic JS date object
var unixtime_ms = date.getTime(); // Returns milliseconds since the epoch
var unixtime = parseInt(unixtime_ms / 1000);
</script>
</p>
<p>
<?php
$option = ['prominent' => 'timestamp'];
?>
<b>Current System time:</b> <?php ui_print_timestamp(time(), false, $option); ?>
<br />
<b>Current Database time:</b>
<?php
global $config;

switch ($config['dbtype']) {
    case 'mysql':
        $timestamp = db_process_sql('SELECT UNIX_TIMESTAMP();');
        $timestamp = $timestamp[0]['UNIX_TIMESTAMP()'];
    break;

    case 'postgresql':
        $timestamp = db_get_value_sql("SELECT ceil(date_part('epoch', CURRENT_TIMESTAMP));");
    break;

    case 'oracle':
        $timestamp = db_process_sql("SELECT ceil((sysdate - to_date('19700101000000','YYYYMMDDHH24MISS')) * (86400)) as dt FROM dual");
        $timestamp = $timestamp[0]['dt'];
    break;
}

ui_print_timestamp($timestamp, false, $option);
?>
<br />
<b>Your browser time:</b> <script type="text/javascript">document.write (date);</script>
</p>