Bug #66187 [Com]: DateTime->add() incorrect on BST boundry

Edit report at https://bugs.php.net/bug.php?id=66187&edit=1 ID: 66187 Comment by: php-bugs at allenjb dot me dot uk Reported by: andrewpate08 at hotmail dot com Summary: DateTime->add() incorrect on BST boundry Status: Assigned Type: Bug Package: Date/time related Operating System: Irrelevant PHP Version: Irrelevant Assigned To: derick Block user comment: N Private report: N New Comment: This issue appears to be fixed as of 5.4.24 / 5.5.8: https://3v4l.org/Q1GCb Previous Comments: ------------------------------------------------------------------------ [2017-03-19 11:16:14] heiglandreas@php.net We're now tracking this in https://bugs.php.net/bug.php?id=74274 ------------------------------------------------------------------------ [2013-12-23 11:12:06] andrewpate08 at hotmail dot com A workround is to switch to UTC to do the arithmetic, something like... $originalTimezone = $targetDateTime -> getTimezone(); $targetDateTime -> setTimezone(new DateTimeZone('UTC')); $targetDateTime -> add($durationAsDateInterval); //add $targetDateTime -> setTimezone($originalTimezone); ------------------------------------------------------------------------ [2013-11-29 22:23:07] bwoebi@php.net http://3v4l.org/7DUjs#v530 There's effectively something wrong: 1 hour 10 mins added in code, but from 27-10-2013 00:55:00+01:00 to 27-10-2013 02:05:00+00:00 2 hours 10 mins are added (=> timezone change is not included) ------------------------------------------------------------------------ [2013-11-27 23:01:39] andrewpate08 at hotmail dot com Description: ------------ British summertime does not actually end until.... 27-10-2013 01:59:59+01:00 (BST) at which point, one second later it kicks back to GMT... 27-10-2013 01:00:00+00:00 (GMT) It seems calculations involving DateTime->add() and the 'Europe/London' DateTimeZone crossing the END of British summertime (BST) gives an incorrect result. On the day British summertime ends it is not until 2:00AM (BST) which is 1:00AM (GMT) that clocks switch from BST to GMT (i.e. go back from 2:00 to 1:00) Test script: --------------- <?php $start = new DateTime("2013-10-27 00:55:00", new DateTimeZone('Europe/London')); $step = DateInterval::createFromDateString("600 seconds"); echo "start = " . $start->format('d-m-Y H:i:sP') . "<br />"; $start->add($step); echo "start = " . $start->format('d-m-Y H:i:sP') . "<br />"; ?> Expected result: ---------------- start = 27-10-2013 00:55:00+01:00 start = 27-10-2013 01:05:00+00:00 Actual result: -------------- start = 27-10-2013 00:55:00+01:00 start = 27-10-2013 01:05:00+01:00 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=66187&edit=1