note 108459 added to datetime.add

Seeing as this add function manipulates the object itself instead of (or in addition to) returning a new object with the result, how does one add an interval to a date, return the new date, and leave the original as it was? For example: $date1 = new DateTime("2012-04-25"); $date2 = $date1->add(new DateInterval("P1Y")); You would expect that: $date1 = 2012-04-25 $date2 = 2013-04-25 But instead BOTH will = 2013-04-25! So, how do you add a time interval to a date, return a result, but not change the original date? ---- Server IP: 69.147.83.197 Probable Submitter: 71.234.104.81 ---- Manual Page -- http://www.php.net/manual/en/datetime.add.php Edit -- https://master.php.net/note/edit/108459 Del: integrated -- https://master.php.net/note/delete/108459/integrated Del: useless -- https://master.php.net/note/delete/108459/useless Del: bad code -- https://master.php.net/note/delete/108459/bad+code Del: spam -- https://master.php.net/note/delete/108459/spam Del: non-english -- https://master.php.net/note/delete/108459/non-english Del: in docs -- https://master.php.net/note/delete/108459/in+docs Del: other reasons-- https://master.php.net/note/delete/108459 Reject -- https://master.php.net/note/reject/108459 Search -- https://master.php.net/manage/user-notes.php