Sunday marks Easter, one the most sacred holidays of the year in Christian tradition.
Easter is meant to celebrate the good news of Jesus’ resurrection, and occurs at the end of the Holy Week, which begins on Palm Sunday and ends on Holy Saturday, comprising the seven days before Easter Sunday.
The days of the Holy Week have not changed in recent tradition: Easter always falls on a Sunday, and the standard definition is that Easter falls on the first Sunday after the full Moon that occurs on or after the spring equinox.
This year, that Sunday is April 20, but as the lunar calendar changes, so too does Easter’s date, and the holiday can take place on Sundays between March 22 and April 25 historically.
Why Easter is always on a Sunday
It’s a longtime tradition. According to the Royal Museums Greenwich in London, “[u]p to the 8th century AD, there was no uniform method for determining the date of Easter.”
The obvious answer to why Easter is on a Sunday, though, lies in scripture: the Gospels state that Jesus was resurrected on the first day of the week, which is Sunday.
But, Matthew Easter, associate professor of biblical studies at Missouri Baptist University, says the consensus that Easter should be celebrated on a Sunday was a much more complicated process than just following the date of Jesus’s resurrection.
“Easter in the Gospels is connected to the Jewish Passover, and Passover can move around any day to week. Early Christians in Asia Minor—like modern day Turkey area—were worshiping Easter the exact day of Passover. So it didn’t have to be a Sunday,” Easter says. “There was this debate among early Christians about whether it should be on a Sunday.”
According to the Bible, Passover takes place on the 14th day of the month of Nissan in the Jewish Calendar, and corresponds with March-April on the civil calendar.
During the reign of the Roman Empire, it became more formalized for Christians to celebrate Easter on Sunday. Around 190 AD, Bishop Victor of Rome decreed that Christians must celebrate Easter on a Sunday, and that Christians who celebrated on Passover—like those in Asia Minor—would be excommunicated, says Easter. Eventually, Bishop Victor backed off his communication threat. In 325 AD, celebrating Easter on Sunday became more official when the Council of Nicaea, convened by Roman Emperor Constantine, decreed that Easter should be observed on the first Sunday following the first full moon after the spring equinox.
Since then, the method conceived at the Council gradually became the accepted method, and Easter has always been celebrated on a Sunday in March or April.
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