The light emitted from Koh Nur was the method of timekeeping with the Sevenfold Mazework and the entire expanse of the Great Dismal Delve. The light also illuminated the entire area.
Twice a day Koh Nur would change color, from light orange to rich purple. The beginning of morning was marked by the orange light trickling from the Mountain of Light and lasted for approximately 13 hours, at which point the light changed to purple and lasted for the same amount of time. All light from Koh Nur was reflected from other strategically placed gemstones located throughout the entire region of the Great Dismal Delve, synchronizing the entire dao nation on the same time schedule.