This useful effect can not only help you transition between scenes, but can completely overhaul the mood or feel of it too.
Night to day or day to night cycles have been used in film and video for decades. To create them realistically (and typically of a landscape rather than a person) you need a time-lapse or a hyperlapse. However, if you restrict the frame enough so that you control the totality of light in that scene, you can fake this effect, which can work as a brilliant transition and alteration of time.
While the idea of gradually raising an bright, orange gelled light is somewhat obvious for a sunrise simulation, I wouldn't have thought to use a cold, blue light and lower that as you raise the other. This gives a polished and convincing effect. My only criticism in the examples is that when you shoot a person this way, it's obvious that it's a trick of the light because of the person's movement, though this could be deemed as creative license of course.
Have you ever faked a night to day cycle? What method did you use?