If the sun move along its celestial path, but never reach the end of the path that is the horizon, then, the sun is not moving in a straight line, but in a circle, or other closed shape, such that it will return to its initial point in the sky.
In the other-realm, this phenomenon is only known to happen in particular places, and only during certain times of the year; after which these places are placed in perpetual darkness for the same period - the Antarctic and Arctic circles of that realm, noted in many a map I have studied of the other-realm, which appears to be rather well documented.
However, in MD, is it possible then, that MD is now placed such that there will be perpetual sunlight, and after a long hiatus, MD will be placed into a perpetual night? Perhaps the day we lose day will be the last for an eternity, and the moon will be our light from then on?
The pillars are broken. What is a pillar, but a support, a structure of strength, connecting and supporting that which it holds. Yet, these are broken, and the connection is lost. If one were to erect pillars and then move the structure supported by these pillars, then, they hold it in place, and then, with sufficient power, the pillars are broken and the support disappears.
I believe the pillars were once used to align the planet. In a different alignment, MD would experience night and day in faster succession, much like the other-realm would, in places not north of the Arctic Circle or south of the Antarctic. However, since the pillars are broken, the planet is now out of alignment, spinning on a new axis, and, as a result, MD land now lies above the equivalent of the Arctic Circle, where it experiences perpetual daylight.
Yet, pillars that are able to support a planet must be incredibly strong. So strong, that no man, however strong, may have the strength to move it. Only the will of a god could move the planet out of alignment with whatever the pillar connected to, and as a result, shatter these pillars. Why would a god wish to shatter the pillars? I would think it would take reasons of mythic proportions.
As said earlier, if the pillars are used to align the planet, they must be connected at one end, to this planet, and on the other, to something else. To what?
It may be that they were connected to another celestial body, or anchored in the aether, or even serve as a link to the god or gods in question.
Something may have happened that resulted in the disassociation of a god with the entire planet.
Or the celestial body, perhaps the Moon, perhaps another, were once anchored to this planet with the pillars - such beings that originated from the Moon may have used these to travel between there and this planet.