Good Friday commemorates the suffering and sacrificial death of Jesus Christ. It is observed by Christians around the world, especially in the Catholic and Anglican countries. For Christians in India, too, it is a day dedicated to fasting, praying, and meditating on the agony and suffering of Jesus. Many churches have a subdued service with solemn hymns and prayers of thanksgiving. The message is centered on observance of the Lord’s Supper and his suffering for his followers. The Friday before Easter Sunday is Good Friday, the day Jesus was crucified. It is also known as Easter Friday, Black Friday, Holy Friday or Great Friday. In Eastern Christianity, which follows the Julian calendar, Easter falls on the first Sunday following the full Moon on or after March 21, the date of the spring equinox. The Western calculation uses the Gregorian or Christian calendar introduced by Pope Gregory XIII in 1582.