How does the flat Earth model explain days being shorter in the winter. while longer in the summer?
Mind that, while in the northern hemisphere it's winter, in the southern hemisphere it's summer, and at the equator there are no changes in day length and sun position on the sky.
And also explain the arctic night and day that last 6 months each (When it's night for 6 months at the north pole, it's day for 6 months at the south pole).