“Maha Shivratri, the night of the worship of Lord Shiva, occurs on the 14th night of the new moon during the dark half of the month of Phalguna. It falls on a moonless February night, when Hindus offer special prayer to the lord of destruction. Shivratri (In Sanskrit, ‘ratri’ = night) is the night when he is said to have performed the Tandava Nritya — the dance of primordial creation, preservation and destruction. The festival is observed for one day and one night only.
Origin of Shivratri
According to the Puranas, during the great mythical churning of the ocean called Samudra Manthan, a pot of poison emerged from the ocean. The gods and the demons were terrified, as it could destroy the entire world. When they ran to Shiva for help, he, in order to protect the world, drank the deadly poison but held it in his throat instead of swallowing it. This turned his throat blue, and because of this he came to be known as ‘Nilkantha’, the blue-throated one. Shivratri celebrates this event by which Shiva saved the world.”