Shivaratri is celebrated as the night of Lord Shiva sometime during February-March. It is believed that Parvati, the wife of Lord Shiva, prayed, meditated and fasted on this day for the well being of Lord Shiva and hoped to ward off any evils that may fall upon him.
On the day of the festival, devotees of Lord Shiva fast and spend the day focused on Lord Shiva, meditating and chanting "Om Namah Shivaya." The Shiva-lingam (a distinguishing representation of Lord Shiva) is decorated with flowers and garlands. It is customary to spend the entire night awake singing the praises of Lord Shiva.