A “calendarium” contains predictions of the positions of the Sun and Moon for several decades into the future. Regiomontanus calculated their positions for 40 years beginning in 1476; Stoeffler for 62 years from 1518-1579 inclusive. From the positions of the Sun and Moon, one may then predict both lunar and solar eclipses. These eclipse predictions were accurate for the time, even though both astronomers were using Earth-centered models.