Description of the etiological factors as ‘Trividha-Hetu’ is unique classification in Ayurveda. Amongst these three factors Kala (time-factor) is beyond the reach of human. It is unavoidable. It is the root cause of climatic changes which we called as seasons i.e. ‘RTU’. Such climatic changes are responsible for development of various signs & symptoms which are known as ‘symptoms due to season change’. To avoid these seasonal illness & maintain health throughout the year, seasonal regimen i.e. Rtucarya is described in Ayurveda. Some signs and symptoms or diseases are likely to occur during the joining period of two consecutive Rtus, specified for two weeks and termed as Rtusandhi. If one disobeys these rules, particularly in Rtusandhi then he mostly suffers from the typical signs and symptoms termed as Asatmyaja Roga in Rtusandhi. Study & practice of Rtucarya helps to prevent the onset of signs and symptoms i.e. ‘Asatmyaja Roga’ in Rtusandhi. This book is based on the fundamental concepts of Ayurveda with survey study of 100 individuals particularly in 3 Rtusandhis. The detailed Rtucarya is also illustrated in this book.