Bug #63311 [Com]: DateTime::add() adds wrong interval when switching from summer to winter time

Edit report at https://bugs.php.net/bug.php?id=63311&edit=1 ID: 63311 Comment by: nj dot johansson at gmail dot com Reported by: thomas dot mayer at 2bis10 dot de Summary: DateTime::add() adds wrong interval when switching from summer to winter time Status: Open Type: Bug Package: Date/time related Operating System: Windows 7, debian 6 PHP Version: 5.4.8 Block user comment: N Private report: N New Comment: Seems like there are many similar reported bugs that might be related to the same underlying issue: https://bugs.php.net/bug.php?id=51051 https://bugs.php.net/bug.php?id=60960 https://bugs.php.net/bug.php?id=61530 https://bugs.php.net/bug.php?id=62331 https://bugs.php.net/bug.php?id=62327 Previous Comments: ------------------------------------------------------------------------ [2014-03-31 11:27:18] nj dot johansson at gmail dot com Experiencing the same thing on PHP 5.4.26 (RHEL 5.6) when subtracting an hour at the time across DST boundary. Test script: --------------- // Init DateTime after DST change $dt = new DateTime('2014-03-30 05:03:00', new DateTimeZone('Europe/Berlin')); $di = new DateInterval('PT1H'); // Subtract one hour each time and notice how time is stuck echo $dt->format('Y-m-d H:i:s') . "\n"; $dt->sub($di); echo $dt->format('Y-m-d H:i:s') . "\n"; $dt->sub($di); echo $dt->format('Y-m-d H:i:s') . "\n"; $dt->sub($di); echo $dt->format('Y-m-d H:i:s') . "\n"; $dt->sub($di); echo $dt->format('Y-m-d H:i:s') . "\n"; Result: ----------------- 2014-03-30 05:03:00 2014-03-30 04:03:00 2014-03-30 03:03:00 2014-03-30 03:03:00 2014-03-30 03:03:00 2014-03-30 03:03:00 ------------------------------------------------------------------------ [2013-07-03 15:01:06] mas at crosscan dot com For me it seems not to be directly connected with switching from or to DST. I tried the following Test script: ---------------- date_default_timezone_set( 'Europe/Berlin' ); $date = new \DateTime( '@0' ); echo $date->format('c')."\n"; $interval = new \DateInterval( 'PT1H' ); $date->add($interval); echo $date->format('c')."\n"; $date->add($interval); echo $date->format('c')."\n"; Expected result: ------------------ 1970-01-01T00:00:00+00:00 1970-01-01T01:00:00+00:00 1970-01-01T02:00:00+00:00 Actual result: ---------------- 1970-01-01T00:00:00+00:00 1970-01-01T02:00:00+00:00 1970-01-01T04:00:00+00:00 ------------------------------------------------------------------------ [2013-05-03 10:30:56] rob dot norman at infinity-tracking dot com I'm seeing similar behaviour across daylight boundaries with CentOS 5.9, PHP 5.4.13 Test script: ------------ $tzLon = new DateTimeZone( 'Europe/London' ); $tzUtc = new DateTimeZone( 'UTC' ); $interval = new DateInterval( 'PT24H' ); // Before change from GMT to BST. $strDt = '2013-04-31 12:00:00'; // Adding the interval in UTC behaves as expected. $dt = new DateTime( $strDt, $tzUtc ); $dt->add( $interval ); echo $dt->format( 'Y-m-d H:i:s' ) . "\n"; // Adding the interval in Europe/London does not. $dt = new DateTime( $strDt, $tzLon ); $dt->add( $interval ); // Convert to UTC for comparison. $dt->setTimeZone( $tzUtc ); echo $dt->format( 'Y-m-d H:i:s' ) . "\n"; Expected result: ---------------- 2013-05-02 12:00:00 2013-05-02 12:00:00 Actual result: -------------- 2013-05-02 12:00:00 2013-05-02 11:00:00 ------------------------------------------------------------------------ [2012-10-19 12:33:35] pajoye@php.net Fix category, tak #2. ------------------------------------------------------------------------ [2012-10-19 12:32:30] thomas dot mayer at 2bis10 dot de I switched Expected result and actual result. Expected result: -------------- 2013-10-27T01:45:00+02:00 1382831100 2013-10-27T02:00:00+02:00 1382832000 900 Actual result: ---------------- 2013-10-27T01:45:00+02:00 1382831100 2013-10-27T02:00:00+01:00 1382835600 4500 ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=63311 -- Edit this bug report at https://bugs.php.net/bug.php?id=63311&edit=1