I've read quite a bit about how the sun and moon allegedly moved in the Flat Earth model, but I really needed to visualize how the 4 seasons worked. So, I got creative with the free software, Stellarium. Now, it should be noted that the programming for Stellarium is based on the heliocentric globe model, however I figured out how to essentially manipulate it in order to show the rotations of the sun and moon over a Flat Earth. What REALLY intrigued me was how the sun literally speeds up and slows down depending on what path it is on during a particular point in the year. I sped the whole animation up (more than 500x) for the sake of time (otherwise, the video would be over an hour long), but other than that, I did not manually adjust the speeds for each season nor do any other (motion) manipulation at all. What you see here is exactly what the software rendered, just overlaid on top of the Flat Earth map. Toward the end, you will see how January and June syncs up day for day perfectly, with a faster sun going around the outer rim and a slower sun moving in the tighter northern circuit.
I based my change of seasons titling as follows...
Spring - starting March 1 and ending May 31,
Summer - starting June 1 and ending August 31,
Fall (autumn) - starting September 1 and ending November 30, and
Winter - starting December 1 and ending February 28
Note: I didn't have time to mess around with day and night as part of this animation. It's just meant to show the seasons and moon phases throughout the year as the sun and moon move above the "circle of the earth." I hope you find this as fascinating as I did.