Bug #60237 [Asn->Dup]: TLA timezone dates produce wrong results with add/diff

Edit report at https://bugs.php.net/bug.php?id=60237&edit=1 ID: 60237 Updated by: danielc@php.net Reported by: stas@php.net Summary: TLA timezone dates produce wrong results with add/diff -Status: Assigned +Status: Duplicate Type: Bug Package: Date/time related Operating System: * PHP Version: 5.4.0beta2 Assigned To: derick Block user comment: N Private report: N New Comment: This is a duplicate of https://bugs.php.net/bug.php?id=55253. Previous Comments: ------------------------------------------------------------------------ [2011-11-07 18:15:45] stas@php.net Description: ------------ If you diff two dates with TLA timezone (like EDT) and then add the interval back to the earliest date, you would not get the later date but instead the result will be one hour off. See example below. Test script: --------------- $start = new DateTime('2010-06-04 02:18:48 EDT'); var_dump($start->format('U')); $end = new DateTime('2010-06-06 18:38:28 EDT'); $ts = $end->format('U'); var_dump($start, $end); $int = $start->diff($end); var_dump($int, $start); var_dump($start->format('U')); $res = $start->add($int); var_dump($res); Expected result: ---------------- ..... object(DateTime)#1 (3) { ["date"]=> string(19) "2010-06-06 18:38:28" ["timezone_type"]=> int(2) ["timezone"]=> string(3) "EDT" } Actual result: -------------- ....... object(DateTime)#1 (3) { ["date"]=> string(19) "2010-06-06 17:38:28" ["timezone_type"]=> int(2) ["timezone"]=> string(3) "EDT" } ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=60237&edit=1