Bug #63953 [Com]: DateTime::diff produces a wrong DateInterval on DST change

Edit report at https://bugs.php.net/bug.php?id=63953&edit=1 ID: 63953 Comment by: alvaro at demogracia dot com Reported by: gianluca dot pinna at allbus dot com Summary: DateTime::diff produces a wrong DateInterval on DST change Status: Open Type: Bug Package: Date/time related Operating System: Linux 64 PHP Version: 5.3.20 Block user comment: N Private report: N New Comment: This looks already fixed in PHP/5.6.0 (2014-08-28) and backport versions released on 2014-09-01: PHP/5.4.24 and PHP/5.5.8 http://3v4l.org/MVWMG Previous Comments: ------------------------------------------------------------------------ [2015-02-17 22:29:35] dev dot anubis at gmail dot com Duplicate of #63442 ------------------------------------------------------------------------ [2014-01-22 14:13:10] perrier dot p at gmail dot com The easy way to see the difference : http://3v4l.org/ab0Hm#v5424 The code <?php $debut = mktime(0, 0, 0, 10, 27, 2013); $fin = mktime(23, 59, 59, 11, 10, 2013); $d1 = new DateTime('now',new DateTimeZone('Europe/Paris')); $d2 = new DateTime('now',new DateTimeZone('Europe/Paris')); $d1->setTimestamp($debut); $d2->setTimestamp($fin); $diff = $d1->diff($d2); print_r($diff); ------------------------------------------------------------------------ [2013-11-06 17:30:09] alvaro at demogracia dot com Yet another test script: <?php $zone = new DateTimeZone('Europe/Madrid'); $start = new DateTime('2013-03-31 1:59:00 ', $zone); $end = new DateTime('2013-03-31 3:00:00', $zone); $difference = $start->diff($end); echo $difference->format('%H:%I:%S') . PHP_EOL; $start->setTimeZone(new DateTimeZone('UTC')); $end->setTimeZone(new DateTimeZone('UTC')); $difference = $start->diff($end); echo $difference->format('%H:%I:%S') . PHP_EOL; ?> Expected output: 00:01:00 00:01:00 Actual output: 01:01:00 00:01:00 ------------------------------------------------------------------------ [2013-06-16 19:23:01] chris at modernmedia dot co I can more or less confirm that DateInterval has Daylight Savings changes backward, at least for my 2014 test cases. In the springtime in the US we spring forward at 2am on a Sunday morning. 2am and 3am are the same exact time, and share the same exact timestamp. At 3am, 2 actual hours have elapsed since midnight. In the fall we fall backward on a Sunday at 2am. In this case, at 3am 4 actual hours have elapsed since midnight. My code shows that DateTime and DateTimezone handle DST changes correctly -- its DateInterval that is having the problem. Here's my test code: <?php /** Daylight Saving Time (United States) 2014 begins at 2:00 AM on Sunday, March 9 and ends at 2:00 AM on Sunday, November 2 */ $tz = new DateTimeZone( 'America/New_York'); $d1 = new DateTime('2014-03-09 00:00:00', $tz); echo PHP_EOL; echo 'Springing forward at 2am on Sunday, March 9, 2014...' . PHP_EOL; for ($n = 0; $n < 7; $n++){ $d2 = new DateTime(sprintf('2014-03-09 %s:00:00', $n), $tz); $ts_diff = ($d2->getTimestamp() - $d1->getTimestamp())/(60 * 60); $int = $d2->diff($d1); echo 'Comparing ' . $d2->format('g a') . ' to ' . $d1->format('g a') . PHP_EOL; echo 'Timestamp diff: ' . $ts_diff . PHP_EOL; echo 'Interval diff: ' . $int->h . PHP_EOL; } echo PHP_EOL; $d1 = new DateTime('2014-11-02 00:00:00', $tz); echo 'Falling backward at 2am on Sunday, November 2, 2014...' . PHP_EOL; for ($n = 0; $n < 7; $n++){ $d2 = new DateTime(sprintf('2014-11-02 %s:00:00', $n), $tz); $ts_diff = ($d2->getTimestamp() - $d1->getTimestamp())/(60 * 60); $int = $d2->diff($d1); echo 'Comparing ' . $d2->format('g a') . ' to ' . $d1->format('g a') . PHP_EOL; echo 'Timestamp diff: ' . $ts_diff . PHP_EOL; echo 'Interval diff: ' . $int->h . PHP_EOL; } phpinfo(INFO_GENERAL); ?> Output ======== Springing forward at 2am on Sunday, March 9, 2014... Comparing 12 am to 12 am Timestamp diff: 0 Interval diff: 0 Comparing 1 am to 12 am Timestamp diff: 1 Interval diff: 1 Comparing 2 am to 12 am Timestamp diff: 2 Interval diff: 3 Comparing 3 am to 12 am Timestamp diff: 2 Interval diff: 3 Comparing 4 am to 12 am Timestamp diff: 3 Interval diff: 4 Comparing 5 am to 12 am Timestamp diff: 4 Interval diff: 5 Comparing 6 am to 12 am Timestamp diff: 5 Interval diff: 6 Falling backward at 2am on Sunday, November 2, 2014... Comparing 12 am to 12 am Timestamp diff: 0 Interval diff: 0 Comparing 1 am to 12 am Timestamp diff: 1 Interval diff: 1 Comparing 2 am to 12 am Timestamp diff: 3 Interval diff: 2 Comparing 3 am to 12 am Timestamp diff: 4 Interval diff: 3 Comparing 4 am to 12 am Timestamp diff: 5 Interval diff: 4 Comparing 5 am to 12 am Timestamp diff: 6 Interval diff: 5 Comparing 6 am to 12 am Timestamp diff: 7 Interval diff: 6 phpinfo() PHP Version => 5.4.9 System => Darwin Christophers-MacBook-Air.local 12.4.0 Darwin Kernel Version 12.4.0: Wed May 1 17:57:12 PDT 2013; root:xnu-2050.24.15~1/RELEASE_X86_64 x86_64 Build Date => Dec 11 2012 12:36:33 ------------------------------------------------------------------------ [2013-02-05 17:42:11] kaido at tradenet dot ee test script: $d1 = new DateTime('2012-05-31'); $d2 = new DateTime('2013-03-02'); $diff1 = $d1->diff ($d2); $diff2 = $d2->diff ($d1); echo "case 1: ".$diff1->m." months, case 2: ".$diff2->m." months"; expected result: both $diff1->m and $diff2->m are 9 ------------------------------------------------------------------------ The remainder of the comments for this report are too long. 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