Minecraft wiki entry for Turtle, associated text: Turtle eggs progress toward hatching by cracking. Cracking occurs during random ticks, and an egg hatches once it has cracked 3 times. When a multi-egg block hatches, all eggs within the block hatch simultaneously. Eggs grow fastest during the night and typically take 4 to 5 in-game days to hatch. See Turtle egg#Hatching for more details.