In Jyotish, Dasha signifies the Graha periods, each influencing various aspects of life based on their positions in the birth chart. The Vimshottari Dasha system is prominent, assuming that an individual's life spans 120 years, distributed among nine Graha periods. These periods, Ketu, Shukra, Surya, Chandra, Mangala, Rahu, Guru, Shani, and Budha, follow a specific order. The pivotal role of Chandra cannot be overstated. The Nakshatra occupied by Chandra at birth determines the initial Dasha period. Subsequent Dasha periods unfold systematically, with their quality influenced by Chandra's Rashi, Nakshatra, and Graha interactions. Assessing Dasha's outcomes involves considering Graha's strengths, placements, aspects, and other factors. The Dasha lord's position within its respective house, exaltation, and interactions with other Grahas in the Kundali all play a significant role. The order and timing of Dasha periods adhere to precise astrological principles. Each Graha period encompasses a range of effects, impacting health, wealth, happiness, and various life facets. This book explores the nuances of the Dasha system, reflecting on how to accurately time events using Vimshottari, one of the most widely used Dashas among practitioners. It also provides an overview of Maharishi Parashara's 42 Dasha systems. It covers two important texts on Vimshottari, Laghu and Madhya Parashari, as a discourse between a teacher and his students.