Maha Shivratri (the 'Great Night of Shiva') is a Hindu festival celebrated every year in reverence of Lord Shiva. It is also known to be the birthday of lord shiva. The Mahashivratri festival, also much popular as 'Shivratri' or 'Great Night of Lord Shiva', is observed on the 13th night/14th day in the Krishna Paksha every year on the month of Maagh according to the Hindu calendar. Alternate common spellings include Sivaratri, Shivaratri, Sivarathri, and Shivarathri. It marks the convergence of Shiva and Shakti. Maha Shivratri is celebrated on the Krishna Paksha Chaturdashi of Hindu calendar month Maagha which falls in February or March as per the Gregorian calendar. Of the twelve Shivaratris in the year, the MahaShivarathri is the most powerful.