Moon phase

The moon in Terraria moves through a cycle of eight different phases, with the next consecutive phase appearing each night. The current moon phase is indicated by the amount of it that is visible each night. The phase of the moon affects, for instance, the shop inventory of certain NPCs or certain enemy spawn rates.

It takes eight in-game nights for the moon to move through all of its phases. The cycle begins with the full moon upon world creation, where the entire circular moon is visible; and four nights later, after three waning phases, reaches the new moon, where no moon is visible. Another four nights later, after three waxing phases, the cycle ends with the return of the full moon.

Each moon phase starts at dawn (4:30AM) and lasts until the next dawn. Therefore, a moon phase also encompasses the day preceding the night of that moon phase. This is important because most phase-dependent content and effects are not limited to nighttime.

The current moon phase can be determined using the Sextant, an informational accessory which can be obtained from the Angler NPC as a fishing quest reward, or any of its upgrades.

A Blood Moon can occur during any moon phase except for a new moon. A Pumpkin Moon or Frost Moon can be summoned by the player on any night.

Phase-dependent content
The following table details items and occurrences that depend on particular moon phases. It refers to both the day and the night of the stated moon phase, unless not applicable or noted otherwise.

Tips

 * If the player does not have access to a, the current moon quarter can be determined by seeing which painting the Painter has for sale, or, in Hardmode, which set of clothes the Clothier has for sale.

Trivia
The phases shown suggest that the Terraria map is set on its world's northern hemisphere: The intermediate phases have their circular side on the right for waxing phases, and the left for waning phases.