A night rating is required to fly during the hours of darkness - officially between half an hour after sunset and half an hour before sunrise.
You'll need to complete at least five hours flight by night of which a minimum of three hours will be dual instruction with one hour as a night navigation sortie. The remainder may be solo and must include five solo take offs and five solo full stop landings.
With me, 3 hours ground school was required.
If Perth-ish means Perth Scotland, I guess you won't being doing much night flying for a few weeks unless your airfield is 24hr or open very late at least.
-bcfc