Description:
------------
When given an invalid date/time both strtotime and the DateTime object returns the 
current day at midnight instead

Test script:
---------------
[adam@nighe]$ php -r '$x=strtotime("2011-00-00");printf("%s\n",date("Y-m-d H:i:s",$x));'
2010-11-30 00:00:00

[adam@nighe]$ php -r '$x=new DateTime("2011-00-00");var_dump($x);'
object(DateTime)#1 (3) {
  ["date"]=>
  string(19) "2010-11-30 00:00:00"
  ["timezone_type"]=>
  int(3)
  ["timezone"]=>
  string(16) "America/New_York"
}


Expected result:
----------------
returns current day at midnight

Actual result:
--------------
strtotime should return FALSE
DateTime should throw an Exception.