PHP date calculation

Question

What is the best (date format independent way) in PHP to calculate difference in days between two dates in specified format.

I tried the following function:

Answer 1

The Zend Framework has the class Zend_Date for dealing with "date math". It works around system specific timestamp limits by using the BCMath extension, or if that's not available limits the timestamps by max float value for your system.

// example printing difference in days
require('Zend/Date.php');

$date1 = new Zend_Date();
$date1->set(2, Zend_Date::MONTH);
$date1->set(27, Zend_Date::DAY);
$date1->set(2008, Zend_Date::YEAR);

$date2 = new Zend_Date();
$date2->set(3, Zend_Date::MONTH);
$date2->set(3, Zend_Date::DAY);
$date2->set(2008, Zend_Date::YEAR);

echo ($date2->getTimestamp() - $date1->getTimestamp()) / (3600*24);