I got this from a Soap client request:
Exception: SoapFault exception: [soap:Client] Server was unable to read request. ---> There is an error i
The problem is with the date format of either $start or $end. Instead of just grabbing the data from the query string with $_GET and sending it over, you need to do some integrity checking to make sure that the date matches the required format
2010-05-24T13:46:00
Instead of using date("Y-m-d") try using:
$startDate = date("Y-m-d") . 'T' . date("H:i:s");