function setnextrestime()
{
    global $lastupdate;
    $newdate = dailyupdatedate();
    // update db.
    $db->query = "UPDATE " . RSSDATA . ".resultsdate SET " . RSSDATA . ".resultsdate.resultdate = '{$newdate}' ";
    $resultuprest = mysql_query($db->query) or die(mysql_error());
}
<?php

session_start();
define('ABSPATH', dirname(dirname(__FILE__)) . '/');
include_once ABSPATH . 'controlpanel/controlhead.php';
$start = $_SESSION[_token];
$t = preventdform();
$_SESSION[_token] = $t;
$tests = $_SESSION[_token];
$testp = $_POST[_token];
$ddate = dailyupdatedate();
?>
<div id="controlsection">  <!-- results date and set -->
<?php 
if (isset($_POST[resultdateid])) {
    if ($_POST[resultnewd]) {
        if ($start == $testp) {
            $newresdate = mysql_real_escape_string($_POST['resultnewd']);
            //echo $newresdate;
            resulttime($newresdate);
            // set date from current
            dateresultform();
        } else {
            dateresultform();
        }
    } else {
        dateresultform();
    }
    // closes else
} else {
    //set the form