laravel/framework — pull request #4505 by prady00 (2014-05-27 15:07:31+00:00)
Title: Fixes #4127

Added php timezone validation rule

```php
protected function validateTimezone($attribute, $value)
{
try
{
new DateTimeZone($value);
}
catch (Exception $e)
{
return false;
}

return true;
}
````