Having a look on the PHP documentation, the following two methods of the
DateTime object would both seem to solve my problem:
Both these methods are marked in the doco as being available in version >= 5.3 (and, not surprisingly, if I try to call them I find they don't exist). I can't find any specific documentation for 5.2.8 so I am not sure if there are equivalent methods in my version. I have Googled the problem and found an eclectic range of solutions, none of which answer my very simple requirements:
For some context, I have the following code:
$st_dt = new DateTime(verifyParam ('start_date')); $end_dt = new DateTime(verifyParam ('end_date')); // is the end date more ancient than the start date? if ($end_dt < $start_dt)
Apparently there is no comparison operator on this guy.
Apparently my assumptions were completely false (thanks Milen for illustrating this so effectively). There is a comparison operator and it works just fine thanks. Sometimes I really miss a compiler. The bug is in the code above, I am sure you will find it much faster than I did :).
The following seems to confirm that there are comparison operators for the DateTime class:
dev:~# php <?php date_default_timezone_set('Europe/London'); $d1 = new DateTime('2008-08-03 14:52:10'); $d2 = new DateTime('2008-01-03 11:11:10'); var_dump($d1 == $d2); var_dump($d1 > $d2); var_dump($d1 < $d2); ?> bool(false) bool(true) bool(false) dev:~# php -v PHP 5.2.6-1+lenny3 with Suhosin-Patch 0.9.6.2 (cli) (built: Apr 26 2009 20:09:03) Copyright (c) 1997-2008 The PHP Group Zend Engine v2.2.0, Copyright (c) 1998-2008 Zend Technologies dev:~#
As of PHP 5.2.2, DateTime objects can be compared using comparison operators.
$date1 = new DateTime("now"); $date2 = new DateTime("tomorrow"); var_dump($date1 == $date2); // false var_dump($date1 < $date2); // true var_dump($date1 > $date2); // false
For PHP versions before 5.2.2 (actually for any version), you can use diff.
$datetime1 = new DateTime('2009-10-11'); // 11 October 2013 $datetime2 = new DateTime('2009-10-13'); // 13 October 2013 $interval = $datetime1->diff($datetime2); echo $interval->format('%R%a days'); // +2 days