/** Hours of this Employee with date >= $date
	* uses SqlSpecs to support eventual joins for sorting 
	* @param date to select the hours by
	* @return arrayn of hours 
	* @throws PntError 
	*/
	function getHoursSince($date='0000-00-00') {
		Gen::includeClass('PntSqlFilter', 'pnt/db/query'); 
		Gen::includeClass('Hours', $this->getClassDir()); // query model needs its metadata
		
		//create filter for employeeId = $this->get('id')
		$employeeIdFilter = PntSqlFilter::getInstance('Hours', 'employeeId', '=', $this->get('id'));
		//ceate a combifilter for ANDing a filter for date >= $date
		$combiFilter = $employeeIdFilter->andWhere('date', '>=', $date);

		//retieve peanuts using the query model
		$clsDes = PntClassDescriptor::getInstance('Hours');
		return $clsDes->getPeanutsAccordingTo($combiFilter); //if the spec is not a PntSqlSort, the default sort will be used
	}