Kalendarium Gregorianum Perpetuum est liber editus a Ecclesia Catholica anno MDLXXXII, qui continet tabulas et regulas pro calculo temporis in perpetuum. Hic liber est opus Gregorii XIII, Papae Romae, qui anno MDLXXXII instauravit calendarii novi rationem, quae nunc usitata est. Kalendarium Gregorianum Perpetuum est utilissimum instrumentum ad calculandum festa mobilia et immobilia, tempora liturgica, et alia tempora sacra. Hoc opus est una ex fundamentis Ecclesiae Catholicae, quae semper curavit ut tempus et liturgia concordarent.This Book Is In Latin.This scarce antiquarian book is a facsimile reprint of the old original and may contain some imperfections such as library marks and notations. Because we believe this work is culturally important, we have made it available as part of our commitment for protecting, preserving, and promoting the world's literature in affordable, high quality, modern editions, that are true to their original work.