private function getHours()
 {
     $hours_cc = new ConstraintChain();
     if (empty($this->_data['week_ending'])) {
         $this->_data['week_ending'] = date(DATE_FORMAT, strtotime('friday'));
     }
     $hours_cc->add(new Constraint('start_time', '<=', fix_date($this->_data['week_ending'])));
     $hours_cc->add(new Constraint('start_time', '>', date('Y-m-d', strtotime('last monday', strtotime(fix_date($this->_data['week_ending']))))));
     if (!isModuleAdmin()) {
         $hours_cc->add(new Constraint('owner', '=', EGS_USERNAME));
     } else {
         if (!empty($this->_data['username'])) {
             $hours_cc->add(new Constraint('owner', '=', $this->_data['username']));
         }
     }
     if (!empty($this->_data['project_id'])) {
         $hours_cc > add(new Constraint('project_id', '=', $this->_data['project_id']));
         //for a single project
     }
     $hours = Hour::getForTimesheet($hours_cc);
     return $hours;
 }