Tracing a crescent arc in the sky, you conjure up a moon. Your moon replaces the real moon in the sky for the duration. This turns day into midnight sharp for the duration, or prolongs the night if cast during nighttime. As soon as the spell ends, your false moon fades away, and the position of the celestial bodies instantly shifts to how it would've been if the sky had not suddenly turned to midnight for the previous hour.
The moon can be any distance away from you or the ground, but unlike the real moon, it is physically a flat crescent that emits light. The shift also has no effect on the flow of time itself, but anything tied to daytime or nighttime will cancel or occur accordingly. Events tied to a specific lunar phase, such as those relying on a full moon, blue moon, new moon, blood moon, or solar eclipse will also be canceled for the duration as a result of the moon being replaced with one that is not spherical enough to obscure sunlight.
* - ((an inkwell and a mushroom or fang))