Maha Shivaratri is a Hindu festival celebrated annually in honour of Lord Shiva , and in particular, marks the day of the celebration of marriage of Shiva . There is a Shivaratri in every luni-solar month of the Hindu calendar , on the month's 13th night/14th day, but once a year in late winter (February/March , or phalgun) and before the arrival of Summer , marks Maha Shivaratri which means "the Great Night of Shiva" .
It is an unique festival of hindus . The people will do fasting whole day and finally at the evening they will eat fruits and they will do jagaram on this day , they will play snakes and ladders during the jagaramand meditating on ethics and virtues such as honesty , non-injury to others , charity , forgiveness ,and the discovery of Shiva .
Visit one of the Shiva temples or go on pilgrimage to Jyotirlingams . This is an ancient Hindu festival whose origin date is unknown .
In Kashmir Shaivism , the festival is called Har-ratri or phonetically simpler Haerath or Herath by Shiva faithfuls of the Kashmir region . Cannabis is also smoked to mark this festival , especially in countries like Nepal and India .

 Why we celebrate maha Shiva ratri : There are many mythological legends associated with this day . According to a popular legend, when a hunter could not find anything to kill for his food in a forest, he waited on the branch of a Woodapple tree . In order to attract deer , he started throwing the leaves of the tree on the ground , unaware that there was a Shiva Lingam beneath the tree . Pleased with the Woodapple leaves and the patience of the hunter , it is believed that Lord Shiva appeared in front of the hunter and blessed him with wisdom . From that day onwards, the hunter stopped eating meat . His name is bakta kanapa . Another legend has it that after the Earth was faced with an imminent destruction , Goddess Parvati pledged with Lord Shiva to save the world. Pleased with her prayers , Lord Shiva agreed to save the world on the pretext that the people of the Earth would have to worship him with dedication and passion . From that day onwards , the night came to be known as Maha Shivratri and people began worshipping Shiva with a great enthusiasm . Some folklore also consider this to be Shiva's day as this was believed to be the answer given by Lord Shiva when asked about his favorite day by Goddess Parvati .

 The History of Shivratri :
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 deathly poison but held it in his throat instead of swallowing it . This made his throat turn blue , and he was given the name Neelakantha , the blue-throated one . Shivaratri is the celebration of this event by which Shiva saved the world .