Most of my springer experience is on the Willamette and Columbia in tidally effected areas. I think in these areas tide plays more of a role on the bite than daylight does. The half hour before and after a tide change are usually the most consistent times to catch fish for me. I've caught them at all times of the tide, but the tide changes are a better bet. I think it's more important to match the lure/bait to the daylight conditions than to worry about intestity of the light.

Aaron