Literally meaning 'Wheel of time'. The teaching was introduced into Tibet in 1027 and it is considered the basis of the Tibetan calendar. Kalachakra is one of the most well-known meditational deities of Anuttarayogatantra. It is associated with the salvific myth of Shambhala and this deity is highly venerated amongst the laity. Most Tibetans try to receive the empowerment of Kalacakra at least once during their life since there is a popular folk belief that attending this empowerment will ensure a birth in the mythical land of Shambhala in the future. However, on a more serious level this tantra is one of the richest sources for the study of the Buddhist systems of cosmology, astrology, astronomy, subtle energy systems, mind/body relationships and various other related topics. The Kalacakra tantra and its commentaries also include profound explanations of the practice of Kalacakra and its theoretical foundations.