<?php

$soapClient = new SoapClient('http://weather.rcware.eu:9876/WeatherForecast',
    array('trace' => 1)); // for debugging: trace = 1

$license = 'myCompanyPrivateLicense'; // sorry, i can't public this
$forecastPointId = 1;
$timeStep = 3600; // seconds

$utcTZ = new DateTimezone('UTC');
$localTZ = new DateTimezone('Europe/Prague');

$utcFrom =  new DateTime('-12hours', $utcTZ );
$utcTo =  new DateTime('+12hours', $utcTZ );


$output = $soapClient->GetWeatherDataInterval(array(
        'license' =>  $license,
        'forecastPointId' =>  $forecastPointId,
        'begin' => $utcFrom->format('Y-m-d\TH:i:s\Z'),
        'end' => $utcTo->format('Y-m-d\TH:i:s\Z'),
        'timeStep' => $timeStep,
        'variableCommonName'  => 'TMAX-2m')
    )->GetWeatherDataIntervalResult->WeatherDataResponse;

echo '<pre>';
var_dump($output);
echo '</pre>';

/* dump:

array(24) {
  [0]=>
  object(stdClass)#8 (4) {
    ["Quality"]=>
    float(0)
    ["TimeStamp"]=>
    string(20) "2013-07-01T18:58:49Z"
    ["Unit"]=>
    string(0) ""
    ["Value"]=>
    float(20.097805344973)
  }
  [1]=>
  object(stdClass)#9 (4) {
    ["Quality"]=>
    float(0)
    ["TimeStamp"]=>
    string(20) "2013-07-01T19:58:49Z"
    ["Unit"]=>
    string(0) ""
    ["Value"]=>
    float(19.062260041762)
  }

  ...
*/

?>