The Physical Occurrence
The celebration referred to as Celestial Rest follows the motions of two planets, a star, and a moon. The star is the one Centoria orbits round, often referred to as the Sun, or in other communities as the Heavenly Star. The two planet are in orbit around this star but are closer in orbit than Centoria so they travel significantly faster. They both have an orbiting path that intersects and covers over the Heavenly Star, from Centoria's perspective, at different time intervals. However, one planet orbits faster than the other so occasionally they will intersect over the planet at the same time. The moon is the one in Centoria's orbit and every once in a while the moon will either block Centoria's view of the sun or Centoria will block the sun from the moons view. The Celestial rest occurs essentially when there is a triple eclipse, which occurs surprisingly for an entire day. When the two planets intersect over the sun and the moon in behind Centoria it is the day of celebration. Since the conditions have to be perfect this occurs once every thirty or forty year.
As the planets block out the sun the colors burst around them and seem to reach toward us. I never look at the moon during this time, seems like such a waste to look away from such majesty to such darkness. I regret that in this life time I will only see it twice.
Most kingdoms see this as a favorable holiday. It is most often celebrated as a renewal of life that all the colors that cascade down from the eclipse are seen as a new life washing over the world. It is a day of rest and in some communities as festivities. There is one peculiarity though, when the eclipse is taking place nearly all magic seems to vanish from the world.
The Martial Community
Those who rely on physical skill for combat and life view this as a good holiday. In some areas around the world they host massive physical competitions to determine the champions of physical capability when there is no possibility for magical interference. Many people say the Celestial Rest Invigorates them and gives them excessive strength during the eclipse.
The Magical Community
All those with strong magical ties detest this holiday. Creature with innate magical properties are able to retain their abilities but they are all significantly weakened during the Celestial Rest. Casters of all kinds find themselves unable to draw the magic necessary to cast more than basic spells. The only magic that still exists are extremely power spells or spell that requires groups of magic users to establish. Magic users spend this holiday in fear mainly. The spent time leading up to it building protections to hold up under the wearing. Often times enemies will uses the Rest to their advantage and hunt down mages that would be untouchable other wise.