Kali Puja, or Shyama Puja, is one of the popular Hindu festivals. Dedicated to the worship of Goddess Kali, Kali Puja falls in the month of October or November on the same day as Deepawali. According to the Bengali calendar, the ritualistic worship is performed on the night of Kartik Amavasya in the Hindu month of Ashwin, just a few days after Durga Puja. As the puja is performed at night, with devotees staying awake and meditating through the night, it is also known as Mahanisha. At present, along with Durga Puja, it is the biggest goddess festival in West Bengal and is celebrated with zestfulness. It is believed that worshipping Goddess Kali cleanses the body and the surroundings of all evil and negative energy. The blessings bestowed by Kali provide longevity and happiness to the worshipper and his family. It is with the same purpose that many a worshippers begin the night long ritual.
But before it all commences, devotees establish clay idols and images of Goddess Kali in their homes and the pandals (temporary shrines or open pavilions). In many homes and pandals, idols and images of Lord Shiva are also established for the reason that He was a consort of Kali. Also, Lord Shiva helped her regain her senses by throwing Himself in the way at the time when she lost sight of what and whom she was destructing in her quest to save the heaven and earth from the demons. Alpana, which are floral designs, are drawn at the entrance of the homes of the devotees, the pandals, or the shrines to welcome the Goddess. Offerings such as red hibiscus flowers, fruits, sweets, sweetmeat, and rice and lentils are also made to her. Some households also follow the tradition of ritualistically dressing Kali in her form of Adya Shakti Kali.
The ritual of sacrificing an animal and offering it to the Goddess Kali, though diminished over the years, still prevails in some parts and is followed by some devotees. At the Kalighat Temple in Kolkata, thousands of devotees gather to offer sacrifices to the goddess. Most of the day is spent in preparing the offerings, sacrificing, decorating the entrances with alpanas, decorating the households and pandals with lights and candles, and eating and celebrating with the family and friends. At night before the puja commences; fireworks, magic shows, and theatre are common sights in the pandals and nearby. All these activities continue through the night. Also, devotees keep moving from one pandal to the other, offering their prayers to the Goddess. At night, the puja commences with tantric rites and mantras that are recited throughout the ritual, till dawn. All this has hardly changed over the period of time and the festival continues to be ever popular among the Bengali and devotees from neighboring states of Orissa and Assam.