Moon

The moon is a celestial body that appears in the night sky.

Nighttime
Nighttime begins after the sun has fully set in the west and the moon has risen in the east. As time passes, the moon moves westward across the sky. Overall, nighttime lasts about 7 minutes (in real-time). Players can track the moon's position in the sky using a clock.

During the night, the moon illuminates the surface in the same manner as the sun; however, light levels fall to a minimum of four. This allows hostile mobs such as zombies and skeletons to spawn.

Grass blocks and saplings do not grow in moonlight, nor do they decay. To grow them at night requires the use of light sources such as torches. On the other hand, crops continue to grow.

Nighttime can be skipped entirely using a bed, provided there are no monsters nearby.

Stars
Together with the moon, the night sky also consists of stars. Stars appear as bright points, and the starfield rotates with the moon as the night progresses. Because they rise in the east and descend in the west, you can navigate by the stars even when the moon is not visible.

Phases


The Moon is always opposite of the Sun, but still goes through eight lunar phases, and changes phase every night. This allows the player to keep rough track of the passage of time, even after spending a few game days underground.

The phases are (in chronological order as they appear in-game):

New Moon Waxing Crescent First Quarter Waxing Gibbous Full Moon Waning Gibbous Third Quarter Waning Crescent

The pixels of the first quarter phase moon and waxing gibbous moon presents a more rounded, organic shape than the corresponding waning phase moons that present a more squared-off appearance. This can help a player in timing a slime hunt in a swamp (see below).

There is no explicit command to change the moon's phase, but using advances time by one day toward the next phase. To go back one phase, using advances time by 7 days, which is one full lunar cycle minus one moon phase.

Effects on mobs


The phase of the moon has two subtle effects on mob spawning:


 * The number of slimes that spawn in swamps is proportional to the moon's fullness: They are most numerous during the full moon and none spawn during the new moon. (The moon's phase does not influence the normal spawning of slimes in designated chunks at altitudes below y=40.)
 * The fuller the moon, the higher the chance skeletons and zombies have the ability to pick up items and spawn with weapons and armor. Furthermore, there is a higher chance for their equipment to be enchanted, and if it is, the enchantment levels are higher. A fuller moon also gives spiders a greater chance to spawn with random beneficial status effects, including invisibility. All of these effects combine with the world's difficulty, and higher difficulty levels increase the chance of mob buffs.
 * During a full moon $$, 50% of cats spawn as black.

Trivia

 * One Minecraft lunar cycle (from full moon to full moon) takes 2 hours 40 minutes of playtime. This means there are approximately 9 lunar cycles in one real-world day (24 hours) of play.
 * Whereas the moon moves independent of other celestial bodies in real life, the Minecraft moon is fixed in the sky relative to the stars. Therefore, solar eclipses are impossible in Minecraft.
 * Standing or flying at a height above the terrain of approximately 1.4× the render distance, the sun appears opposite to the moon in the sky, making it seem almost as if the player is in space.
 * The moon appears to be lit from the north or south, whereas it should be lit from the east or west (by the sun). Being fixed opposite to the sun, it should be constantly full.
 * The star pattern is based on a seed, but not the current world's seed. Like the bedrock pattern, the stars are always based on the same seed, regardless of the world seed.