The 14th day of the dark half of Krsna Chaturdasi is called 'Sivaratri' or 'Maha-Sivaratri'.

The one in the month of Magha (February-March) is christened 'Mahasivaratri', since it is the greatest of all.

Of all the major Hindu festivals, Mahasivaratri is the only one wherein the austerity part (as signified by the very word 'vrata') is predominant. There is practically no festivity, revelry or gaiety in its observance, the whole thing being one of continuous solemnity. This is but natural since Shiva is the god of the ascetics, the very Sada Shiv.

This vrata is open to all human beings. The basic disciplines to be kept up on this day are ahimsa (non-injury), satya (speaking the truth), Brahmacharya (continence), daya (compassion), Ksama (forgiveness) and anasuyata (absence of jealousy).

Fasting is one of the most essential aspects of this vrata. So also jagarana or keeping vigil in the night. Worship of Siva throughout the night, bathing the Sivalinga with panchamrta (five tasty things- milk, curds, ghee, sugar and honey), homa, japa of the mulamantra (basic mantra, viz., Om Namas Sivaya) and prayer for forgiveness- are the other items involved in its observance.