From: alessio at alias2k dot com Operating system: Debian 6 PHP version: Irrelevant Package: *General Issues Bug Type: Bug Bug description:Date object
Description: ------------ --- >From manual page: http://www.php.net/datetime.sub#refsect1-datetime.sub- description --- When you have a datetime object you can modify the date adding or subtracting month. If you do that, the result is always unpredictable, because the mktime, the sub, or the modify function, always subtract the amount of days of the previous month. I'll make an example: If I do <?php $date = new DateTime('2001-03-31'); $interval = new DateInterval('P1M'); $date->sub($interval); echo $date->format('Y-m-d'); ?> I obtain 2001-03-03 as result, but I've expected to have 2001-02-28, because the previous month is february, not 28 days first. We have the same problem if we add some months to our starting date: <?php $date = new DateTime('2001-03-31'); $interval = new DateInterval('P1M'); $date->add($interval); echo $date->format('Y-m-d'); ?> I obtain 2001-05-01 as result, but also in this case I've aspected a different result, i think the right value is 2001-04-30, because you have to add the days of the next month to obtain the right result, not the days of current month. . The problem is also the communication with mySql, because mySql calculate the right result, so the comparison between two date it's impossible Test script: --------------- <?php $date = new DateTime('2001-03-31'); $interval = new DateInterval('P1M'); $date->sub($interval); echo $date->format('Y-m-d'); ?> Expected result: ---------------- 2001-02-28 Actual result: -------------- 2001-03-03 -- Edit bug report at https://bugs.php.net/bug.php?id=64347&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=64347&r=trysnapshot54 Try a snapshot (PHP 5.3): https://bugs.php.net/fix.php?id=64347&r=trysnapshot53 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=64347&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=64347&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=64347&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=64347&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=64347&r=needscript Try newer version: https://bugs.php.net/fix.php?id=64347&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=64347&r=support Expected behavior: https://bugs.php.net/fix.php?id=64347&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=64347&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=64347&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=64347&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=64347&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=64347&r=dst IIS Stability: https://bugs.php.net/fix.php?id=64347&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=64347&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=64347&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=64347&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=64347&r=mysqlcfg