When Ben and Kate are out on there first date and they get a small boat out to the navy ship then get on to the cleaners ledge or whatever you want to call it, it is clearly night time and is pitch dark. But when they are just about to kiss and the camera angle changes, it is light behind them. Then in the next scene, it's back to darkness!
I thought this at first when I saw the movie as well. But, since the boat behind them is a bright light-bluish color, from one angle, it looks like the sky. But when the view is from far away, you can see that the boat is what makes it look like daylight.