"Kalacakra and the Tibetan Calendar describes the contents of current Tibetan almanacs, from the most basic mathematics to the symbolic and historical information they contain. Essential for understanding the Kalacakra Tantra's first chapter, it traces and describes the origin of the calendrical systems in the Kalacakra Tantra, and it translates and elucidates the key relevant sections from the famous commentary to this Tantra, the Vimalaprabha." "The main calendars in use in Tibet today have remained unchanged since the 15th century, when lamas in several different traditions tried to make sense of the calculation systems they had inherited from India, and to adjust them to remove increasingly obvious errors in their results. This book analyzes the main systems that survive today, assessing their accuracy and comparing them with the methods described in the original Tantra."--BOOK JACKET.