How to create a day and night effect?

Hi,

I am drawing a house (shaped as a cube with a triangular roof) and a couple of lamp posts next to it. The ground is rendered as a sandy patch.

How do I create a day and night effect using openGL lights? For night time, the environment (the house and the sandy patch) is supposed to be dimmed to simulate the darkness and the lamp posts are supposed to light up.

How do I manipulate the lights to achieve the night time dimming effect? Is it to change the ambient light to black?
And how do I enable the lamp posts to light up? Do I use diffuse or emissive lights?

Day time is ok. When the picture is rendered, the scene looks quite bright already. I think i'll just have to turn off the lights for the day time effect.

For daylight, I make sure my textures colors are RGB(255, 255, 255) for full color, and night, RGB(55, 55, 55), for a darker color, even for the skybox. And when you have your lights, it gives that effect you are looking for.