Wrong gmstrtotime() value checks

Hi, I'm using "rules_data_type_date" Class to handle rules with dates objects, but the rules_data_type_date::check_value() returns a valid date even if it's input value is wrong.

The main reason rely on "rules_gmstrtotime($time)" function that, if the given $time parameter is an invalid string, it returns "1970-01-01 00:00:00".
This is caused by the unchecked return value of php strtotime() function invocation: it returns FALSE if the given time is not valid.

IMHO rules_gmstrtotime() should return NULL if the given parameter is invalid, and then rules_data_type_date::check_value() must check if NULL is returned.

Snippet from *new* rules_gmstrtotime() function

    // If the time string is not in plain old date format (e.g. 'now', '+1 day'
    // etc.), we need to convert it first.
    $value = strtotime($time);
    if ($value === FALSE)
      return NULL;
    $date = gmdate('Y-m-d H:i:s', $value);
    return strtotime($date .' UTC');
  } 

Suggested *new* rules_data_type_date::check_value() implementation

    function check_value($info, $value) {
      if (is_numeric($value)) {
        $value = gmdate('Y-m-d H:i:s', $value);
      }
      else if (is_string($value) && ($time = rules_gmstrtotime($value)) != NULL) {
        $value = gmdate('Y-m-d H:i:s', $time);
      }
      if (is_string($value) && preg_match(RULES_DATE_REGEX_LOOSE, $value)) {
        return $value;
      }
    }

Regards