Holi is a major festival in the Hindu religion. It is celebrated on the day after the last full moon of the Hindu month of Phalguna. Phalguna falls between late February and early March in Western calendars.
Holi celebrates the Hindu story of Prahlada. Prahlada was a prince dedicated to the worship of Vishnu, a major Hindu god. Prahlada's father and aunt opposed his religious faith, and as punishment made him sit in the middle of a raging bonfire. Vishnu protected Prahlada, and the prince did not burn.