Sankranti (Sanskrit: संक्रान्ति, romanized: Saṁkrānti) refers to the transmigration of the sun from one zodiac to another in Indian astronomy. In Saurmana varsha (Hindu Solar year), there are twelve Sankrantis corresponding with twelve months of a year. The Sankrantis can be broadly classified into four main categories: Ayan (Solstice), Vishuva (Equinox), Vishupadi and Shadshitimukhi sankrantis. Each Sankranti is marked as the beginning of a month in the sidereal solar calendars followed in South Indian states: Andhra Pradesh, Telangana, Tamil Nadu, Kerala, Karnataka; Himalayan states: Jammu region, Himachal Pradesh, Uttarakhand, North Punjab and states of Eastern India: Odisha, Mithila region of Bihar and Nepal. On the other hand, in the sidereal solar Bengali calendar and Assamese calendar, a Sankranti is marked as the end of each month and the day following as the beginning of a new month.