ad_manager_api/lib/ad_manager_api/ad_manager_api_datetime.rb
def method_missing(name, *args, &block)
      result = @date.send(name, *args, &block)
      return self.class.new(@api, result) if result.is_a? Date
      return result
    end
def method_missing(name, *args, &block)
      result = @date.send(name, *args, &block)
      return self.class.new(@api, result) if result.is_a? Date
      return result
    end
When an unrecognized method is applied to AdManagerDate, pass it through
 to the internal ruby Date.