Corrected entry: At Helms Deep, just before the battle, they see the sun rising through the window. But in the next shots - from the outside - the castle is still in the shadow - and the sun only rises when Gandalf appears.
Jacob La Cour
24th Nov 2007
Correction: The sunlight shines through the window of the keep because the sky lightens, not because the sun is shining directly at the castle window. When Gandalf arrives at the top of the hill, we see the keep is in a valley. The sunlight follows his arrival because it rises enough to crest the hilltop the Rohirrim are waiting atop, then gradually shines across the Uruk-Hai army below them.