While not a fishing reg guideline, I've noticed many park wardens and their ilk interpret "dawn to dusk" in such a manner as to mean "whenever I say." This almost stung me once on a local lake which is behind a mountain that obscures the sunset...it gets "dark" there 45 minutes before the other side of the island! On this note, I've got to commend the fishing regs for their clarity in regards to "one hour before official sunrise to one hour past official sunset."