What is Maha Shivaratri?
Maha Shivaratri, the "great night of Shiva", falls on the fourteenth night of the waning moon in Magha. Unlike most festivals it is dated by what is happening at *midnight* rather than at sunrise, because the vigil, not the daylight, is the observance.
How it is observed
Devotees fast through the day and keep watch through the night, offering water, milk and bilva leaves to the Shiva linga in four watches. The Nishita Kaal window below is the most auspicious of them.