You must have seen a sunrise at some point in your life, or perhaps experienced a daytime getting towards twilight and then it being night-time ? Like for example, you go out to play, and your mammy (or whoever) says 'be in before [whatever] o'clock', or just 'be back before it gets dark', or at some point you'll have been out during the daylight then it got to be night, yeah, so the time passed - the Sun seems to have changed position, because the Earth is rotating around.