Bug #55461 [NEW]: date_modify() affects variables recursive?!

From: Operating system: Win7 PHP version: Irrelevant Package: Date/time related Bug Type: Bug Bug description:date_modify() affects variables recursive?! Description: ------------ --- From manual page: http://www.php.net/function.date-modify --- I'm sorry if I did do something wrong and waste your time, but I can't explain this behaviour: date_create() gets assigned to a variable >>> $now this variable ($now) is being copied to another variable ($later) and this new variable ($later) then modified with date_modify() to be 30 days in the past ODD BEHAVIOUR: after this is executed BOTH variables, $now and $later are 30 days in the past? Test script: --------------- <?php $now = date_create(); # get current datetime $later = $now; # copy $now to $later date_modify($later,'-30 day'); $now_str = date_format($now,'Y-m-d H:i:s'); $later_str = date_format($later,'Y-m-d H:i:s'); echo "\$now_str: ".$now_str."</br>"; echo "\$later_str: ".$later_str."</br>"; ?> /* $now_str: 2011-07-20 22:05:31 $later_str: 2011-07-20 22:05:31 */ -- Edit bug report at https://bugs.php.net/bug.php?id=55461&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=55461&r=trysnapshot54 Try a snapshot (PHP 5.3): https://bugs.php.net/fix.php?id=55461&r=trysnapshot53 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=55461&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=55461&r=fixed Fixed in SVN and need be documented: https://bugs.php.net/fix.php?id=55461&r=needdocs Fixed in release: https://bugs.php.net/fix.php?id=55461&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=55461&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=55461&r=needscript Try newer version: https://bugs.php.net/fix.php?id=55461&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=55461&r=support Expected behavior: https://bugs.php.net/fix.php?id=55461&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=55461&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=55461&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=55461&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=55461&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=55461&r=dst IIS Stability: https://bugs.php.net/fix.php?id=55461&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=55461&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=55461&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=55461&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=55461&r=mysqlcfg