Recall that the sun makes one orbit per day around in the Mithlond disc. This orbit is in a plane that begins the year parallel and slightly lower than the disc. At the beginning of the year, there is no sunlight as the sun is behind the rim mountaints the entire day.
As the year progresses, the plane rotates about an axis parallel to the Mithlond North-South axis so that 90 days into the 360 day year, the plane if the suns orbit is perpendicular to the plane of the disc. On this day, for those people living along the North-South axis, the sun passes directly over head with the sun rising in the north and setting in the south.
At 180 days into the year, the sun's plane is once again parallel to the disc and again there is no sunlight. Beyond the 180 day mark, the sun once again rises above the rim mountains but since the sun's orbital plane is "flipped over" the sun appears to move in the opposite direction across the sky as it did during the first 180 days.
At 270 days, the solar plane is again perpendicular to the disc plane and again the sun passes directly overhead for people on the North-South axis but this time it rises in the south and sets in the north.
- beginning of year, no sunlight
- as year progresses, the sun rises in the north and sets in the south each day rising higher in the sky and the sun peaking in the easy until-
- day 90 when it is at its highest in the sky and peaks directly over the center of the world disc
- after day 90, it now starts setting, with the peak in the west until-
- at day 180 the sun is completely behind the rim mountains after which-
- the sun start rising, peaking higher and higher in the east but now rising in the south and setting in the north until-
- day 270 at which, like day 90, it is highest in the sky
- then it starts setting, with the peak in the west until
- the start of the new year when the sun is completely begind the rim mountains again