function format_date($format, $time) {

    $format = str_replace(

        ['%a', '%A', '%d', '%e', '%u', '%w', '%W', '%b', '%h', '%B', '%m', '%y', '%Y', '%D', '%F', '%x', '%n', '%t', '%H', '%k', '%I', '%l', '%M', '%p', '%P', '%r', '%R', '%S', '%T', '%X', '%z', '%Z', '%c', '%s', '%%'],

        ['D', 'l', 'd', 'j', 'N', 'w', 'W', 'M', 'M', 'F', 'm', 'y', 'Y', 'm/d/y', 'Y-m-d', 'm/d/y', "\n", "\t", 'H', 'G', 'h', 'g', 'i', 'A', 'a', 'h:i:s A', 'H:i', 's', 'H:i:s', 'H:i:s', 'O', 'T', 'D M j H:i:s Y', 'U', '%'],

        $format

    );



    $date = DateTimeImmutable::createFromFormat('U', $time);



    return $date->format($format);

}

function showdate($format, $val) {

    global $settings, $userdata;



    if (isset($userdata['user_offset'])) {

        $offset = $userdata['user_offset'] + $settings['serveroffset'];

    } else {

        $offset = $settings['timeoffset'] + $settings['serveroffset'];

    }

    if ($format == "shortdate" || $format == "longdate" || $format == "forumdate" || $format == "newsdate") {

        return format_date($settings[$format], $val + ($offset * 3600));

    } else {

        return format_date($format, $val + ($offset * 3600));

    }

}

$date_opts .= "<option value='".$dateformat."'>".strftime($dateformat, $timestamp)."</option>

$date_opts .= "<option value='".$dateformat."'>".format_date($dateformat, $timestamp)."</option>";

<td width='50%' class='tbl'>".strftime($settings2['longdate'], (time())+($settings2['serveroffset']*3600))."</td>

<td width='50%' class='tbl'>".format_date($settings2['longdate'], (time())+($settings2['serveroffset']*3600))."</td>

<td width='50%' class='tbl'>".strftime($settings2['longdate'], time()+(($settings2['serveroffset']+$settings2['timeoffset'])*3600))."</td>

<td width='50%' class='tbl'>".format_date($settings2['longdate'], time()+(($settings2['serveroffset']+$settings2['timeoffset'])*3600))."</td>