Maha Shivaratri is a Hindu festival celebrated annually in honour of the god 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 Phalguna) and before the arrival of spring, marks Maha Shivaratri which means "the Great Night of Shiva".

It is a major festival in Hinduism, but one that is solemn and marks a remembrance of "overcoming darkness and ignorance" in life and the world. It is observed by remembering Shiva and chanting prayers, fasting, doing Yoga, and meditating on ethics and virtues such as self-restraint, honesty, noninjury to others, forgiveness, and the discovery of Shiva. The ardent devotees keep awake all night. Others 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.

Description
Maha Shivaratri is an annual festival dedicated to the Hindu god Shiva, and is particularly important in the Shaivism tradition of Hinduism. Unlike most Hindu festivals which are celebrated during the day, the Maha Shivaratri is celebrated at night. Furthermore, unlike most Hindu festivals which include expression of cultural revelry, the Maha Shivaratri is a solemn event notable for its introspective focus, fasting, meditation on Shiva, self study, social harmony and an all night vigil at Shiva temples.

The celebration includes maintaining a "jaagaran", an all-night vigil and prayers, because Shaiva Hindus mark this night as "overcoming darkness and ignorance" in one's life and the world through Shiva. Offerings of fruits, leaves, sweets and milk to Shiva are made, some perform all-day fasting with vedic or tantric worship of Shiva, and some perform meditative Yoga. In Shiva temples, "Om Namah Shivaya", the sacred mantra of Shiva, is chanted through the day.

Maha Shivaratri is celebrated over three or ten days based on the Hindu luni-solar calendar. Every lunar month, there is a Shivaratri (12 per year). The main festival is called Maha Shivaratri, or great Shivaratri, and this is on 13th night (waning moon) and 14th day of the month Phalguna (Magha). According to the Gregorian calendar, the day falls in either February or March.

History and significance
According to Jones and Ryan, the festival may have originated around the 5th century CE.

The Maha Shivaratri is mentioned in several Puranas, particularly the Skanda Purana, Linga Purana and Padma Purana. These medieval era Shaiva texts present different mythologies associated with this festival, but all mention fasting and reverence for icons of Shiva such as the Lingam.

Different legends describe the significance of Maha Shivaratri. According to one legend in the Shaivism tradition, this is the night when Shiva performs the heavenly dance of creation, preservation and destruction. The chanting of hymns, the reading of Shiva scriptures and the chorus of devotees joins this cosmic dance and remembers Shiva's presence everywhere. According to another legend, this is the night when Shiva and Parvati got married. A different legend states that the offering to Shiva icons such as the linga is an annual occasion to get over past sins if any, to restart on a virtuous path and thereby reach Mount Kailasha and liberation.

The significance of dance tradition to this festival has historical roots. The Maha Shivaratri has served as a historic confluence of artists for annual dance festivals at major Hindu temples such as at Konark, Khajuraho, Pattadakal, Modhera and Chidambaram. This event is called Natyanjali, literally "worship through dance", at the Chidambaram temple which is famous for its sculpture depicting all dance mudras in the ancient Hindu text of performance arts called Natya Shastra. Similarly, at Khajuraho Shiva temples, a major fair and dance festival on Maha Shivaratri, involving Shaiva pilgrims camped over miles around the temple complex, was documented by Alexander Cunningham in 1864.

In India
The major Jyotirlinga Shiva temples of India, such as in Varanasi and Somnatha, are particularly frequented on Maha Shivaratri. They serve also as sites for fairs and special events.

The Isha Yoga Center near Coimbatore in Tamil Nadu is frequented during the festival. Around 600,000 to 800,000 devotees participate in the all-night festival conducted by Sadhguru, and visit the 112-foot Adiyogi Shiva statue at the center.

The Mandi fair is in the town of Mandi is particularly famous as a venue for Maha Shivaratri celebrations. It transforms the town as devotees pour in. It is believed that all gods and goddesses of the area, said to number more than 200, assemble here on the day of Maha Shivaratri. Mandi, located on the banks of Beas, is popularly known as the "Cathedral of Temples" and one of the oldest towns of Himachal Pradesh, with about 81 temples of different Gods and Goddesses on its periphery.

Maha Shivaratri is the most important festival in Kashmir Shaivism, found in north Himalayan region of the Indian subcontinent. It is celebrated as the anniversary of the marriage of Shiva and Parvati.

Central India has a large number of Shiva followers. The Mahakaleshwar Temple, Ujjain is one of the most venerated shrines consecrated to Shiva where a large congregation of devotees gathers to offer prayers on the day of Maha Shivaratri. Tilwara Ghat in the city of Jabalpur and the Math Temple in the village of Jeonara, Seoni are two other places where the festival is celebrated with much religious fervour.

In Gujarat mahashivratri mela is held at Junagadh where bathing in the Damodar Kunda is considered holy.According to myth Lord Shiva himself comes to bath in the Damodar kunda.

Maha Shivaratri is celebrated widely in the temples all over Maharashtra, Andhra Pradesh, Karnataka, Kerala, Tamil Nadu and Telangana.

In Nepal
Maha Shivaratri is a National Holiday in Nepal and celebrated widely in temples all over the country, but especially in the Pashupatinath temple. Thousands of devotees visit the famous Shiva Shakti Peetham nearby as well. The Nepalese army parades around the city of Kathmandu to pay tribute to Lord Shiva, and holy rituals are performed all over the nation. Artists from various classical music and dance forms perform through the night. On Maha Shivaratri, married women pray for the well being of their husbands, while unmarried women pray for a husband like Shiva, considered as the ideal husband. Shiva is also worshipped as the Adi Guru (first teacher) from whom the yogic tradition originates.

Outside South Asia
Maha Shivaratri is the main Hindu festival among the Shaiva Hindu diaspora from Nepal and India. In Indo-Caribbean communities, thousands of Hindus spend the auspicious night in over four hundred temples across the country, offering special jhalls (an offering of milk and curd, flowers, sugarcane and sweets) to Lord Shiva. In Mauritius, Hindus go on pilgrimage to Ganga Talao, a crater-lake.

https://en.wikipedia.org/wiki/Maha_Shivaratri