Masi Magham is one of the auspicious festivals of Hinduism, celebrated with pomp and piety in the Tamil month of Masi, which corresponds to February-March in the Gregorian calendar. Masi Magham happens once a year. Once in twelve years, when Jupiter enters the Simha or Leo constellation, Masi Magham is celebrated as Maha Magham. Magham is one among the twenty-seven stars or Nakshatras. This festival is associated with the cleansing ritual, which people observe on this day to get rid of their sins. A bath in holy rivers or seas during the festival is considered auspicious for attaining salvation. This is not only famous across Tamil Nadu, but also across the places where Tamil-Hindus are settled in large numbers.
Source by AstroVed