Hi!

I've had a look at this, and now I can tell you what happens.
Without the delimiter, the 800 gets parsed as 80 hours, 0 minutes.
If you add 80 hours to  11.11.2009, that means 3 days, 8 hours, you get 14.11.2009, 8am.

If you call DateTime::getLastError, you see it shows a warning:

derick@whisky:~$ cat /tmp/test.php 
<?php
$dt = DateTime::createFromFormat( 'd.m.Y Gi', '11.11.2009 800' );
var_dump($dt);
var_dump(DateTime::getLastErrors());
echo $dt->format( 'd.m.Y G i' );
?>

derick@whisky:~$ php /tmp/test.php 
class DateTime#1 (3) {
  public $date =>  string(19) "2009-11-14 08:00:00"
  public $timezone_type =>  int(3)
  public $timezone =>  string(13) "Europe/London"
}
array(4) {
  'warning_count' =>
  int(1)
  'warnings' =>
  array(1) {
    [14] =>
    string(27) "The parsed time was invalid"
  }
  'error_count' =>
  int(0)
  'errors' =>
  array(0) {
  }
}
14.11.2009 8 00
derick@whisky:~$ 

The parser for "G" parses up to 2 characters, and it doesn't know how to stop if it encounters something too high. I'm looking at how I can changes this, but still not break BC in any form. I've changed the bug's status to FR now.

cheers,
Derick

This is similar to this example:

<?php
$date = DateTime::createFromFormat('MjY', 'Jan92014');
var_dump($date);
var_dump(DateTime::getLastErrors());

which outputs:

class DateTime#1 (3) {
  public $date =>
  string(19) "0014-04-02 18:24:29"
  public $timezone_type =>
  int(3)
  public $timezone =>
  string(13) "Europe/Zurich"
}
array(4) {
  'warning_count' =>
  int(1)
  'warnings' =>
  array(1) {
    [8] =>
    string(27) "The parsed date was invalid"
  }
  'error_count' =>
  int(0)
  'errors' =>
  array(0) {
  }
}

Technically you could know where to stop based on the fact that Y is 4 digits and M is 3 characters, but understand that parsing left-to-right makes this difficult.

As of PHP 5.3.9, this fails[1], and I think we can leave it at
that.

[1] <https://3v4l.org/XRpio>