Time zone bug with \DateTimeInterface::diff()

[jack-worman]

Description

The following code:

<?php

function getYearsBetween(
    \DateTimeImmutable $startDate,
    \DateTimeImmutable $endDate,
): int {
    $dateInterval = $startDate->diff($endDate, true);
    return $dateInterval->y;
}

$start = new \DateTimeImmutable('2000-11-01 09:29:22.907606', new \DateTimeZone('America/Chicago'));
$end = new \DateTimeImmutable('2022-06-06 11:00:00.000000', new \DateTimeZone('America/New_York'));
$result = getYearsBetween($start, $end);
var_export($result);

Resulted in this output:

-22

But I expected this output instead:

21

There seems to be a timezone issue that breaks \DateIntervals
Works (same time zones): https://3v4l.org/RK34h
Does not work (different time zones): https://3v4l.org/nmPAj

In the mean time, I will be ensuring both \DateTimeImmutables are in the same timezone before calling ->diff()

PHP Version

>= 8.1.10

Operating System

No response

[heiglandreas]

That looks like the documentation of the parameter absolute is a bit ... off?

[hormus]

The return value more specifically represents the clock-time interval to apply to the original object ($this or $originObject) to arrive at the $targetObject. This process is not always reversible.

Without absolute

<?php

$start = new \DateTime('2000-11-01 09:29:22.907606', new \DateTimeZone('America/Chicago'));
$end = new \DateTime('2022-06-06 11:00:00.000000', new \DateTimeZone('America/New_York'));
$result = $start->diff($end);
var_export($result->y);

?>

Yes bug, DateTimeImmutable from php 5.5.0, diff from php 5.3.0 expected result is 21.

<?php
$utc = new \DateTimeZone('UTC');
$london = new \DateTimeZone('Europe/London');

$test1 = new \DateTime('2018-01-31', $utc);
$test2 = new \DateTime('2018-03-31 00:00:00', $london);

$dateDiff = $test2->diff($test1); // true absolute Should the interval be forced to be positive
//$dateDiff = $test1->diff($test2);
$bugs = array('y' => &$dateDiff->y, 'm' => &$dateDiff->m, 'd' => &$dateDiff->d, 'h' => &$dateDiff->h, 'invert' => &$dateDiff->invert, 'days' => &$dateDiff->days);
$test3 = new \DateTime('+2 month ' . $test1->format('Y-m-d\\TH:i:s\\Z'));

var_dump($test3->format('Y-m-d H:i:s +00:00'), $bugs, $dateDiff->format('%r%a'));

?>

Expected result: (only php < 8.1.10)

string(26) "2018-03-31 00:00:00 +00:00"
array(6) {
  ["y"]=>
  int(0)
  ["m"]=>
  int(1)
  ["d"]=>
  int(30)
  ["h"]=>
  int(23)
  ["invert"]=>
  int(1)
  ["days"]=>
  int(58)
}
string(3) "-58"

Expected result $dateDiff = $test1->diff($test2): (only php < 8.1.10)

string(26) "2018-03-31 00:00:00 +00:00"
array(6) {
  ["y"]=>
  int(0)
  ["m"]=>
  int(1)
  ["d"]=>
  int(27)
  ["h"]=>
  int(23)
  ["invert"]=>
  int(0)
  ["days"]=>
  int(58)
}
string(2) "58"

[derickr]

Now fixed, for PHP 8.1.14 and PHP 8.2.1.