text: what classifies sunrise?when we have daylight or when you can see the sun on the horizon?   good question. it's the sort of thing that seems so obvious -- but everyone has a different opinion about just what the correct answer is. in some parts of the world, sunrise happens when you can distinguish between a black thread and a white one - in other words, when the day begins to become light. in other places it isn't until the sun is actually on the horizon. it's pretty spectacular to watch the sun rise in the grand canyon -- it literally runs down the walls of the canyon, revealing things you never see at any other time of day, until it hits the bottom of the canyon.  the actual definition must have to do with daylight, because if it were when we saw the sun on the horizon, that means there would never be a sunrise on a cloudy or rainy day.  'but that's just my opinion.