[Endoperez]

That is how the effects stack... The descriptions of the spells would seem to incline some connection between the darkness and the sun. Mainly, something being in the way of the sun most of the time. If there are two suns, the light gets through the cover more often. It still isn't enough to give the world more light than there would normally be.

Some kind of a glasshoubd effect could do, but this is a fantasy game...