Reports are texts that are written in various languages and periods. The basis of the writings of all Muslim historians (Arabic and Persian histories), has been the official Khwaday-Namag of the Sassanian court that have utilized the recorded diaries in the official calendars of the court as references. Khwaday-Namag was prepared at the ends of the Sassanian era in Middle Persian language. The title of the Arabic translation of the book was Seir-ol Moluk-el Ajam and the Persian version was Shahnameh. Today, none of the direct translations of Khwaday-Namag or its original Persian text are available.