This spell is similar to a light spell, except that it is as bright as full daylight and lasts until negated by magical darkness or by a dispel magic spell. Creatures who suffer penalties in bright light suffer them in this spell's area of effect.
As with the light spell, it can be cast into the air, onto an object, or at a creature. In the third case, the spell affects the space about one foot behind a creature that successfully rolls its saving throw vs. spell.
Note that this spell can also blind a creature if it is successfully cast upon the creature's attack rolls, saving throws, and Armor Class by 4.
If the spell is cast on a small object that is then placed in a light-proof covering, the spell's effects are blocked until the covering is removed.
A continual light brought into an area of magical darkness (or vice versa) is temporarily negated so that the otherwise prevailing light conditions exist in the overlapping areas of effect. A direct casting of continual light against a similar or weaker magical darkness cancels both.
This spell eventually consumes the material it is cast upon, but the process takes far longer than the time in the typical campaign. Extremely hard and expensive materials can last hundreds or even thousands of years.