Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to report
a bug at http://bugs.php.net/how-to-report.php

This is not a bug. 2011 is seen as time instead:

php -r 'var_dump(date_parse("2011, February 8"));'
array(12) {
  ["year"]=>
  bool(false)
  ["month"]=>
  int(2)
  ["day"]=>
  int(8)
  ["hour"]=>
  int(20)
  ["minute"]=>
  int(11)
  ["second"]=>
  int(0)
  ["fraction"]=>
  bool(false)
  ["warning_count"]=>
  int(0)
  ["warnings"]=>
  array(0) {
  }
  ["error_count"]=>
  int(0)
  ["errors"]=>
  array(0) {
  }
  ["is_localtime"]=>
  bool(false)
}

you right; this is not a bug.
but i think the "Y, F j" is much more common than "Hi, F j".
and many application like Drupal use "Y, F j" as a default date format. so parsing date as "Hi, F j" rather than "Y, F j" would cause confiusing errors in applications.
I suggest replace the priorities of two format mentioned.

You already have DateTime::createFromFormat() if you wish to parse other formats.

Yes; but I meant the default behavior of strtotime() is not appropriate now.
and i think it is absolutely better that something like "2011, February 8" parses as "Y, F j" instead of "Hi, F j".

Perhaps, but we can't just change how the parser works. Others might perhaps rely on this.