Description:
------------
When you use the 'z' format character after the time ('H:i:s z'), the time information gets parsed incorrectly. If you use the 'z' char in front of the time ('z H:i:s'), it parses fine.

Affected versions are 7.1.0RC4 and 7.1.0RC5: https://3v4l.org/QOS7s

Test script:
---------------
<?php

$date = '12:00:00 15';
$format = 'H:i:s z';

var_dump(DateTime::createFromFormat($format, $date));

Expected result:
----------------
object(DateTime)#1 (3) {
  ["date"]=>
  string(26) "2016-01-16 12:00:00.000000"
  ["timezone_type"]=>
  int(3)
  ["timezone"]=>
  string(16) "Europe/Amsterdam"
}

Actual result:
--------------
object(DateTime)#1 (3) {
  ["date"]=>
  string(31) "2016-01-16 11:59:55.-2147483648"
  ["timezone_type"]=>
  int(3)
  ["timezone"]=>
  string(16) "Europe/Amsterdam"
}