PHP 8.1 - DateTime::createFromFormat returns false

[capsandiego]

Description

The following code (which works perfectly in PHP 8.0:

<?php
var_dump(DateTime::createFromFormat('z Y', '147 2022'));

Resulted in this output:

bool(false)

But I expected this output instead:

object(DateTime)#2 (3) {
  ["date"]=>
  string(26) "2022-05-28 15:36:32.000000"
  ["timezone_type"]=>
  int(3)
  ["timezone"]=>
  string(16) "America/New_York"
}

The only way to make it work is to swap day of the year and year.

PHP Version

PHP 8.1.6

Operating System

Ubuntu Server 18.04

[iluuu1994]

Note that this changed in PHP 8.0.10. https://3v4l.org/N2MlJ

The docs also match the behavior.

https://www.php.net/manual/en/datetime.createfromformat.php

format character	Description	Example parsable values
z	The day of the year (starting from 0); must be preceded by Y or y.	0 through 365

Note the word "preceded", and flipping the modifiers does actually solve the issue.
https://3v4l.org/2tXJd

But I'm not sure if this is an accidental or wanted change. Maybe @derickr can clarify.

[capsandiego]

You are absolutely right! Evidently I missed the 8.0.10 changes (and the docs which is very clear)
Many thanks for the quick response!

[iluuu1994]

No problem. Let's keep it open until Derick responds just to make sure this is expected.

[derickr]

This is expected. The parser works from left to right, and without knowing the year, you don't know whether for example 147 is either May 28 in 2022, or the also correct May 27 in leap years. The fix in 8.0.10 makes this now a hard requirement as per the documentation instead of sometimes giving you the wrong answer (As it would have used the current year, 2022, to calculate the 147th day there).