Maha Shivaratri is the festival celebrated during the night and is completely dedicated to Lord Shiva, who is also known as the destroyer of evil and the remover of ignorance. The Puranas describe some stories to explain the myth about ‘why is Shivarathri celebrated during the night time. Maha Shivratri 2012 date is February 20.
The ‘Amavasya, (a full dark night), which comes just after the day of Shivarathri, also represents the ‘Kalyug. To enter safely and prosperously into the Kali yuga, people worship Lord Shiva to give courage and pleasure by demolishing evil and removing ignorance.