Question: I have the below line of codes 

```
$day1 = new Zend_Date('2010-03-01', 'YYYY-mm-dd');
$day2 = new Zend_Date('2010-03-05', 'YYYY-mm-dd');
$dateDiff = $day2->getDate()->get(Zend_Date::TIMESTAMP) - $day1->getDate()->get(Zend_Date::TIMESTAMP);
$days = floor((($dateDiff / 60) / 60) / 24);
return  $days;  

```

this will return 4

But if gave 

```
$day1 = new Zend_Date('2010-02-28', 'YYYY-mm-dd');
$day2 = new Zend_Date('2010-03-01', 'YYYY-mm-dd');
$dateDiff = $day2->getDate()->get(Zend_Date::TIMESTAMP) - $day1->getDate()->get(Zend_Date::TIMESTAMP);
$days = floor((($dateDiff / 60) / 60) / 24);
return  $days; 

```

it will return -27 .. how will i get right answer

Answer: 
I believe the problem is in your part string. Try **YYYY-MM-dd** instead.

```
$day1 = new Zend_Date('2010-02-28', 'YYYY-MM-dd');
$day2 = new Zend_Date('2010-03-01', 'YYYY-MM-dd');
echo $day2->sub($day1)->toString(Zend_Date::DAY);

```
I've extended `Zend_Date` for my own convenience functions. My solution is similar to Nisanth's, with some key differences:

1. calculate the beginning of the day for both days before comparing
2. use `round()` instead of `ceil()`
3. do not add `1` to the result

Example code:

```
class My_Date extends Zend_Date
{
    public static function now($locale = null)
    {
        return new My_Date(time(), self::TIMESTAMP, $locale);
    }

    /**
     * set to the first second of current day
     */
    public function setDayStart()
    {
        return $this->setHour(0)->setMinute(0)->setSecond(0);
    }

    /**
     * get the first second of current day
     */
    public function getDayStart()
    {
        $clone = clone $this;
        return $clone->setDayStart();
    }

    /**
     * get count of days between dates, ignores time values
     */
    public function getDaysBetween($date)
    {
        // 86400 seconds/day = 24 hours/day * 60 minutes/hour * 60 seconds/minute
        // rounding takes care of time changes
        return round($date->getDayStart()->sub(
            $this->getDayStart()
        )->toValue() / 86400);
    }
}

```