The sun and moon rise and set in Survivalcraft, and the moon changes phases nightly. They will often be obscured by cloud cover, however. In creative mode, you can set the time of day or night, and they will not move across the sky.
The sun will rise at dawn and set at dusk. It emits a vivid orange and pink coloration in the morning and evening. Once it reaches noon, the sun is at its zenith - its highest point in the sky, and the day is half over.
The moon rises as the sun sets and vice-versa. It goes through 8 phases.
Each phase takes one SurvivalCraft day. So the SC month is only 8 days long. When the moon is at its zenith the night is half over.
The day/night cycle in Survivalcraft worlds is 20 minutes long (real time).
The sun and moon are in lockstep and never pass each other in the sky. This actually makes the moon phases nonsensical. But the changing phases do give the appearance of Earth-like nightly variation.
During the new moon (only the outline of moon is visible) or full moon (all of moon is visible) wolves near the player may transform into werewolves during the night.
New Moons give off less light than regular moons and the full moon is brighter.
The light levels for various times of day are given on the Photodiode#Lighting_values photodiode page.