The Kalachakra tantra has been held sacred and preserved in both India and Tibet for over 2500 years. The Kalachakra tantra helps purify the body and mind. Kalachakra literally means, Time wheel or Time Circle. Some sections of the Kalachakra tantra have been lost over time, but the beginning parts of this tantra still remain. The proper name for the Kalachakra tantra is the Kalachakra Laghuntantra.
The Kalachakra tantra is thought to be the most advanced form of Vajrayana Buddhism, and it is most prominent in the Jonang tradition of Tibetan Buddhism. The circles of time are associated with the rotations of the planets and moon cycles, breath cycles, and even the cycles of our bodies.
There are both inner and outer realms to the Kalachakra tantra. This idea of an inner realm and an outer realm is common in both Buddhism and Hinduism. The outer realm is also known as the gross realm. The inner realm is also known as the subtle realm. This consists of what is apparent on the surface. The inner realm consists of the interior workings of things, such as the relationship of internal energies and the chakras. The inner and outer realm of the Kalachakra tantra can be thought of like the relationship of body and mind and how these two correspond to one another.
There are five chapters in the Kalachakra tantra. The first two chapters deal with the outer realm and the last three deal with the inner realm. The first chapter is also known as the ground kalachakra, and it relates to the physical world. The second chapter refers to the inner world. The third chapter concerns the preparation for the meditation practices. The fourth chapter is about the meditation itself, and the fifth chapter describes the enlightenment available from the practices.
The Kalachakra tantra is most commonly taught to monks and other serious Buddhist practitioners after a period of initiation. This initiation period prepares the practitioner to practice the Kalachakra tantra is their quest for Buddhahood.
The Dalai Lamas are particularly concerned with the Kalachakra practice, including the current Dalai Lama. The 14th Dalai Lama