Its not

Shivariti or something

Its Shiva-Ratri ( Ratri : Night). Observed as the night of Shiva. One of the biggest Hindu festivals. Remembering Shiva and chanting prayers, fasting, doing Yoga and meditating.

Devotees of Lord Shiva fast for the whole day and pray for noninjury to others, forgiveness, and the discovery of Shiva.
Om Namah Shivaya (sacred mantra of Shiva).