[boost] Getting a xsd:datetime from boost::date_time

Hi, (sorry if this is off topic) I need to get the current date and time and convert it into a string that follows the xsd:datetime time stamp format: [-]CCYY-MM-DDThh:mm:ss[Z|(+|-)hh:mm]. (timezone should be UTC) Any ideas on how to do that? The Boost::Date_Time library documentation is confusing to my feeble mind. Thanks, Joe