It has a real-time day/night cycle, where real-time day is the same in-game, and vice versa. However, time can be flipped temporarily (as long as the pickaxe power) using the Circadian Pickaxe's pickaxe power.
During daytime, Dawn Stone can be found in this biome. But when night comes, Dusk Stone will appear instead. The Dawn Stone and Dusk Stone is required to obtain the Sun banner and the Moon Banner.
There are 10 types of blocks in this biome: Amber, Dawn Stone, Dusk Stone, Red Mushroom, Green Mushroom, Brown Mushroom, Cursed Earth, Mycelium, and Acacia Wood. Additionaly, Circadian Dust can be made in the furnace.