Ambience
Changes the world appearance properties.
Real World Time
Follow your computer's clock instead of a fixed time. Real midnight maps to in-game midnight and real noon to in-game noon, so the sky tracks the actual time of day.
Time
The tick to hold the world at when Real World Time is off. 0 is sunrise, 6000 is noon,
12000 is sunset, and 18000 is midnight.
Light tint
Tint the light the world is lit with, so blocks, mobs and players take on its colour. The sky, clouds and HUD keep their normal colours. Off by default.
Sky tint
Colour of daylight and moonlight, and of the faint light in the darkest spots. Its alpha is how strongly the light takes it on, so a low alpha gives a subtle grade and full alpha colours the light completely. Defaults to a soft warm tone.
Block tint
Colour of light from torches, lava and other light sources, with alpha working the same way. Minecraft whitens block light as it gets brighter, so this shows most in the dimmer light a few blocks away from a source. Defaults to a warm orange.
Both follow the colour picker's THEME and CHROMA modes too.