[PHP82] DateTime modify does not work with addition of minus values

[shyim]

Description

The following code:

<?php
$a = (new \DateTimeImmutable('2022-05-01 22:00:00'))->modify('+-30 seconds');

var_dump($a);

Resulted in this output:

Adds 30 seconds

But I expected this output instead:

Should substract 30 seconds like before

https://3v4l.org/6eMQj

It did work before RC3. I am not sure if this is intended or not 😅

PHP Version

PHP 8.2.0 RC6

Operating System

macOs Ventura 13.1 Beta 2

[derickr]

You are right that this is a change, but it is expected and on purpose to fix another bug: derickr/timelib@44cfe97 / derickr/timelib#124

It now picks the first sign that it finds... although perhaps it should warn on the second sign. In any case, the workaround is to change the +- to just - in your code.

[derickr]

FWIW, the original behaviour was pretty much a bug, so I don't think we need to do anything here, and hence I'm closing this issue.

[aquavark]

@derickr I know you closed this, but I just wanted to add that this change also affected strtotime, which broke applications under test in 8.2 in a non-obvious manner (caused duplication of dates in a dynamic built array that then caused data overwriting) and I couldn't find it listed as a PHP 8.2 breaking change anywhere. I've requested to see if PHPStan or PHPCompatibility (for codesniffer) can help detect this as a breaking change. As it was accepted methodology previously (albeit not to the written standard, I accept that) it may cause other breakages that are non-obvious.