If it was a flat disc, the days would not be getting longer south of the equator right now.

OP is posting from New Zealand. Hey Kiwi brian, the only explanation for the days getting longer on your side of the globe while they are getting shorter on our side is that we are on a globe spinning on a tilted north south axis.

You can duplicate the phenomenon of the Arctic midnight sun with a flashlight and a globe in a darkened room.

You can also duplicate the Arctic midnight sun with a flashlight and a frisbee or plate, but you cannot duplicate the Antarctic midnight sun with a frisbee. You can with a globe.