Legend
Shiva being an ascetic god, Maha Shivratri is very popular with ascetics. Thandai- a drink made with cannabis, almonds, and milk, is essentially drunk by the devout. This is so because cannabis is said to have been very dear to Shiva. The Puranas contain many stories and legends describing the origin of this festival.
According to one, during the Samudra Manthan, a pot of poison emerged from the ocean. This terrified the gods and demons as the poison was capable of destroying the entire world and they ran to Shiva for help. To protect the world from its evil effects, Shiva drank the deadly poison but held it in his throat instead of swallowing it. Because of it, his throat turned blue and he was given the name Nilkantha- the blue-throated one. Shivratri is the celebration of this event by which Shiva saved the world.
Maha Shivaratri festivals Video