Every month in the Hindu calendar has listed the thirteenth day of the darker half of the month as Shivaratri i.e. 'Shiva's great night'. The Shivaratri which falls in the krishna paksha of the month of Magha is celebrated all over the country as 'Mahashivaratri'. As the name indicates this festival is celebrated in honour of Shiva, the third God of the Hindu Trinity. This is one time when the Hindus of all castes and creeds get together to observe this day with a fast and pious exercises. The peculiar feature of this festival is that the night before the feast the devotees keep an all night vigil. To stay awake the whole night is very important for every Hindu as it adds up to ones merits. The devotees spend the night singing hymns, reading sacred texts and other such religious activities. The Puranas say that those who keep an all night vigil on Shivaratri will be rewarded will material prosperity and paradise after death.
The exact origins of the fast are unknown, but the festival has been mentioned in the Mahabaharata. The lore of the festival goes as follows:-
There was once a hunter by the name of Lubdhaka. He made his living by hunting wild animals and selling the flesh to the villagers. But once he could not pay off his debt to the creditor and he accumulated huge arrears. His creditor went to the court and had him arrested and confined to the prison for non-payment of his debts. It so happened that his prison cell was near the Shiva temple of the village. All day long he heard the devotees come into the temple and worship the deity and repeat the Lord's name. Not being particularly religious he was unaware of the deity's existence. Out of sheer boredom he too started repeating Shiva's name after the devotees, almost mocking them. By the evening he was released from prison by the kind courtesy of a wealthy man who had paid off his debt. Just by repeating the Lord's name mechanically he had earned for himself his release.
Later that night he went to hunt as usual and hid himself on a tree which was a Bel tree. Under the tree unknown to him was a Shiva Linga. While making a place for himself to sit on the tree the Bel leaves fell on the Linga. Now the Bel leaves are extremely sacred to Shiva and its offering is very pleasant to the deity. Waiting for the prey to arrive he kept an all night vigil. Around midnight, a doe, young and in labour came to the tree. The hunter took aim but the doe pleaded for her life and promised to return to him after delivering her young one. Lubdhaka took pity on her and let her go. Next came another doe seeking her mate. The hunter once again took aim but again the doe asked to be spared and the man against his will let her go. This doe too promised to return in the morning. Then came along a black buck looking for his mate, but he too was spared after it promised to return.
Unknowlingly, the hunter has observed the fast of the Shivaratri. He was rewarded by being made a saint. The Lord himself escorted him to heaven.
It is believed that if one has to worship Shiva he/she must follow a very strict regimen. The Lord is offered bel leaves, ketaki flowers, dhatura, milk, rice, water. This is one time when all the people irrespective of caste and creed take part in the rituals. There are no restrictions as to who can or cannot observe this fast.