Dot Porter, Curator, Digital Research Services at the University of Pennsylvania Library, offers a video orientation to Penn Library’s LJS 300, Calendarium and ephemerides, by Joannes Regiomontanus. This manuscript was written in Lambach, Austria, ca. 1500, in Latin. Manuscript copy of the Calendarium and Ephemerides as published by Regiomontanus in 1474. The Calendarium, for 1475-1530, gives information on lunar and solar eclipses, the length of days, and the signs of the zodiac and planets. Also includes a table of time corrections (f. 11v) for cities in reference to a longitude of approximately 10 degrees east (thus making no correction for Braunschweig, Nuremberg, Ulm, or Milan). The Ephemerides, consisting only of tables updated to begin in 1480 and ending in 1506, provides positions for the sun, moon, and planets for each day of each year.