<p style='text-align: justify;'>Introduction to a treatise on the calendar. Describes the history of calendrical knowledge from the time of the prophets, through the times of elders and scholars, up to the author’s own time, when this knowledge, transmitted orally in the past, diminished. The author states that people rely heavily on the intercalation of R. Josiah b. Mevoraḵ because it is easy to learn, but the copies of this work differ among themselves and are faulty. </p>