$ php -v
PHP 5.3.10-1ubuntu3.9+wmf1 with Suhosin-Patch (cli) (built: Dec 13 2013 17:12:38) 
Copyright (c) 1997-2012 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2012 Zend Technologies
    with Xdebug v2.1.0, Copyright (c) 2002-2010, by Derick Rethans
$ hhvm --version
HipHop VM v2.3.2 (rel)
Compiler: heads/HHVM-2.3-0-g3fa32fab6e2373a26a5ba6167b750eeaaf0052c2
Repo schema: e163dcc55f565103c06bfcdb714b619a58ba4e3a
$ php -r "var_dump( date_create( '19420713250502' ) );"
bool(false)
$ hhvm --php -r "var_dump( date_create( '19420713250502' ) );"
object(DateTime)#1 (0) {
}
$ php -r "var_dump( new DateTime( '19420713250502' ) );"
PHP Fatal error:  Uncaught exception 'Exception' with message 'DateTime::__construct(): Failed to parse time string (19420713250502) at position 12 (0): Unexpected character' in Command line code:1
Stack trace:
#0 Command line code(1): DateTime->__construct('19420713250502')
#1 {main}
  thrown in Command line code on line 1

Fatal error: Uncaught exception 'Exception' with message 'DateTime::__construct(): Failed to parse time string (19420713250502) at position 12 (0): Unexpected character' in Command line code on line 1

Exception: DateTime::__construct(): Failed to parse time string (19420713250502) at position 12 (0): Unexpected character in Command line code on line 1

Call Stack:
    0.0001     626480   1. {main}() Command line code:0
    0.0001     627336   2. DateTime->__construct() Command line code:1

$ hhvm --php -r "var_dump( new DateTime( '19420713250502' ) );"
object(DateTime)#1 (0) {
}