Zend_date functions

Zend_Date.php

<?php
 $currentDate = new Zend_Date();
                    $currentDate->setDate($taskDistribution["date"], "yyyy-MM-dd");
                    $startTime = new Zend_Date();
                    $startTime->setTime($taskDistribution["start_time"], "HH:mm:ss");
                    $endTime = new Zend_Date();
                    $endTime->setTime($taskDistribution["end_time"], "HH:mm:ss");
                    if($endTime->toString('HH') == '00')
                        $endTime->setHour('24');

                    $taskDayTotal += $endTime->sub($startTime)->toValue()/60/60;
                
            
            $taskWeekTotal=0;
            
            if(isset($staff["TaskDistribution2"]))
            foreach($staff["TaskDistribution2"] AS $taskDistribution){
                $startTime = new Zend_Date();
                $startTime->setTime($taskDistribution["start_time"], "HH:mm:ss");
                $endTime = new Zend_Date();
                $endTime->setTime($taskDistribution["end_time"], "HH:mm:ss");
                if($endTime->toString('HH') == '00')
                        $endTime->setHour('24');
                
                $taskWeekTotal += $endTime->sub($startTime)->toValue()/60/60;
            }
            if(isset($currentDate)){
                $currentDate->setTime("12:00:00 AM")->toString();