Sunday, April 20, marks Easter, one of the most revered holidays within the Christian tradition. This occasion is celebrated to commemorate the joyous resurrection of Jesus Christ, a pivotal event that symbolizes hope and renewal for millions around the world. Easter falls at the conclusion of Holy Week, a significant period that begins with Palm Sunday and culminates on Holy Saturday. Holy Week encompasses seven days leading up to Easter Sunday, and this structure has remained consistent throughout recent traditions.

The date of Easter is not fixed and varies each year. This year, Easter falls on April 20, but historically, the holiday can be observed on any Sunday between March 22 and April 25. The determination of Easters date is intricately tied to the lunar calendar, which shifts annually. The formula for calculating Easter is rooted in the ecclesiastical approximation of the March equinox, stating that Easter is celebrated on the first Sunday following the first full moon that occurs on or after the spring equinox.

But why is Easter always celebrated on a Sunday? This longstanding tradition is grounded in scripture. According to the Gospels, Jesus was resurrected on the first day of the week, which is Sunday. Matthew Easter, an associate professor of biblical studies at Missouri Baptist University, explains that the consensus on celebrating Easter on a Sunday was established through a much more intricate process than simply aligning with the day of Jesus's resurrection. He notes, Easter in the Gospels is connected to the Jewish Passover, and Passover can vary from any day of the week. Early Christians in Asia Minormodern-day Turkeywere actually celebrating Easter on the exact day of Passover, so it didnt have to necessarily be a Sunday.

The debate among early Christians regarding the observance of Easter on a Sunday versus Passover was significant. In the Jewish calendar, Passover occurs on the 14th day of Nissan, which falls within the March-April timeframe of the civil calendar. During the Roman Empire, the celebration of Easter on Sunday became increasingly formalized. Around 190 AD, Bishop Victor of Rome issued a decree mandating that Christians must celebrate Easter on a Sunday. He also threatened excommunication for those who continued to observe the holiday on Passover, such as the early Christians in Asia Minor. However, Bishop Victor later retracted his excommunication threats.

The pivotal moment in the formalization of Easter's date occurred in 325 AD when the Council of Nicaea, convened by Roman Emperor Constantine, declared that Easter should be celebrated on the first Sunday following the first full moon after the spring equinox. This decision established a standardized method for calculating Easter's date, a practice that has continued to the present day. As a result, Easter has been consistently celebrated on a Sunday in either March or April for nearly two millennia, serving as a testament to the enduring legacy of this sacred holiday.