Sidereal months refer to the time it takes for the moon to complete one orbit around the Earth with respect to fixed stars. Other synonyms for sidereal months include lunar sidereal months, stellar months, and orbital months. These terms are used interchangeably in astronomy to describe the moon's orbital period, which differs slightly from its synodic period. Synodic months are the time it takes for the moon to return to the same phase, like the new moon or full moon, and are approximately 29.5 days long. In contrast, sidereal months last about 27.32 days and are vital for predicting eclipses and other celestial events.