Easter is the greatest and most important feast of the Catholic liturgical year, celebrating the Resurrection of Jesus Christ from the dead on the third day after His crucifixion. It is the foundation of the entire Christian faith — as St. Paul wrote, 'If Christ has not been raised, your faith is vain' (1 Corinthians 15:17). The Easter celebration begins with the Easter Vigil on Holy Saturday night, considered the 'mother of all vigils.' This magnificent liturgy includes: (1) The Service of Light — the Easter fire is lit, and the Paschal candle is processed into the dark church. (2) The Liturgy of the Word — up to nine readings tracing salvation history. (3) The Liturgy of Baptism — catechumens are baptized, confirmed, and receive their first Communion. (4) The Liturgy of the Eucharist. Easter Sunday Mass continues the celebration with joyful hymns, the ringing of bells, and the proclamation 'He is risen!' Easter is not just one day but an entire season lasting 50 days until Pentecost, making it the longest liturgical season. The date of Easter varies each year, calculated as the first Sunday after the first full moon following the spring equinox.