Zend_Date::sub() and ISO_8601 calculating hour difference wrong

[vekFrelve]

I want to calculate time difference between two Zend_Date objects (for countdown calculator):\[code\]$now = new Zend_Date($now_datetime, Zend_Date::ISO_8601);$end= new Zend_Date($end_datetime, Zend_Date::ISO_8601);echo $now->getIso(); echo $end->getIso();$expires=array();$expires['expired']=false;if($end->isEarlier($now)){ $expires['expired']=true; return $expires;}$dif=$end->sub($now);$expires['days']=($dif->getDay()->toValue()/(60*60*24));$expires['hours']=($dif->getHour()->toValue()/(60*60));$expires['minutes'] = $dif->getMinute()->toValue()/60;$expires['seconds'] = $dif->getSecond()->toValue();var_dump($expires);\[/code\]For $now_datetime ='2012-06-30 01:01:01' and $end_datetime='2012-06-30 23:59:59', the result is\[code\]2012-06-30T01:01:01+02:002012-06-30T23:59:59+02:00//array'expired' => boolean false'days' => int 0'hours' => int 22'minutes' => int 58'seconds' => int 58\[/code\]and it is OK.But for For $now_datetime ='2012-06-30 00:01:01' and $end_datetime='2012-06-30 23:59:59', the result is\[code\]2012-06-30T00:01:01+02:002012-06-30T23:59:59+02:00//array'expired' => boolean false'days' => int 1'hours' => int -1'minutes' => int 58'seconds' => int 58\[/code\]and it is NOT OK. I expect 'hours' to be 23, not -1 ?!I am running MAMP with php 5.3, Zend_Framework 1.10.What is wrong with that? ISO_8601 is used for MySQL 'datetime' data and I don't wanto to change to mktime()...