End of Days

One day will be the final day, but we will not know it until it has already ended.
When you cast this spell, you summon a massive sphere of magical darkness far above the world that moves perfectly in tune with the rise and set of the sun. In effect, it is always night within the range of this spell, and all natural sunlight that would be cast upon that area is blocked by the sphere. The material component used to cast this spell must be placed at a point where the sky is clearly visible, and if it is moved more than 5 feet in any direction, the spell immediately ends.