During twilight or the hours of darkness, when must you have your side lights switched on as a minimum requirement?

You answered correctly. In Germany, at twilight or during hours of darkness, vehicles parked on the hard shoulder outside built-up areas must have their side lights switched on as a minimum. This is important for safety so the parked vehicle is visible to other road users in low-light conditions. However, when driving on roads with adequate continuous lighting, using side lights alone is not enough—you need dipped headlights. Always ensure you use the right lights to match the situation for safety and to follow the rules.