Orthodox celebrate Pascha later

This year, Orthodox Christians are celebrating the Feast of the Lord's Resurrection five weeks after Roman Catholics and Protestants celebrate Easter. Sometimes we all celebrate it together on the same day, sometimes with a one week, four week or five week difference. What's the story behind this?
For this year, the difference in calculations has boggled me, even as a priest. I was told as a child that Orthodox Pascha must come after the Jewish Passover, since Christ was our Passover Lamb, sacrificed for us. But some years the Roman Catholic Easter also comes after Jewish Passover, so that can't be it. But before we go any further, maybe you noticed a difference in terminology.
Orthodox Christians often use the term "Pascha," the Greek word for Passover, in describing their celebration of the Lord's Resurrection. This is because the word "Easter" comes from the ancient Germanic festival of the Spring Equinox -- a pagan holiday. The pagan heritage of Easter is what gives us things like the Easter bunny, a symbol of fertility. Thus, I will use Pascha to refer to the Orthodox feast and Easter for the Roman Catholics and Protestants.
Jewish Passover
Jewish Passover, according to the Old Testament, is to be celebrated on the 14th day of the lunar month of Nisan in the Jewish calendar. Since lunar months start from new moon to new moon, this might fall on any day of the week. The year of the Lord's death and Resurrection it happened that the Passover was on a Saturday. Therefore, the Lord Jesus Christ, the Lamb of God who is sacrificed for us and takes away the sin of the world, was slaughtered on Friday, the Day of Preparation, with the lambs prepared for the Jewish holy day.
On Passover, a Sabbath that year, He rest within the tomb. On Sunday, the first day of the week, He rose from the dead, trampling down death by death. This was the first Christian Pascha, the model for our future celebration.
The earliest Christians kept the annual memory of the festival, especially in conjunction with the Jewish Passover, since the two groups were still closely tied. Christians of the East continued to observe Pascha as immediately following Passover, so it could fall on any day of the week. Christians in Rome and Alexandria kept the celebration on the Sunday after Passover. So early on even a united Church had different dates.
Eventually, as the Church became less and less Jewish and more unified throughout the Roman Empire, there was a need to formalize the dating of Pascha.
St. Constantine
Here enters our beloved St. Constantine, the emperor who ended the bloody persecution of Christians and made it possible for the Church to freely preach the gospel. For that alone he is revealed as blessed. He's also a good litmus test for one's Orthodoxy.
If one believes, as does Dan Brown, author of the "DaVinci Code," and other non-Orthodox believers that Constantine generally meddled with the Church and compromised it with innovations, then it's extremely likely the rest of one's beliefs are going to stray widely from Orthodoxy, probably because one lacks good common sense and/or listens to everything one hears on TV.
Among Constantine's supposed meddling is that he called the Church to convene a great council of its bishops to settle its internal disputes. He recognized that a factionalized, bickering Church was an ineffective church and would do little to help bring peace and healing to a civilization that had been tearing itself apart for too long.
One of the simpler issues the first council, the Council of Nicaea, decided was when unified Christians would celebrate Pascha. It was determined then that it should be the first Sunday after the first full moon after the spring equinox, and that they should follow the Roman's Julian Calendar for determining the equinox (generally March 21). In this way, the Church could celebrate Pascha biblically without depending on the Jewish Calendar. Constantine was happy, everyone was happy -- at least for a while.
Now the Julian calendar was the best of its kind at the time, but like all man-made things, it was subject to error. Over the centuries the Calendar lost several days so that the actual spring equinox was happening earlier and earlier, which pushed Pascha later into the season.
Refusing change
Orthodox astronomers were some of the first to recognize this and propose adjustments, but later emperors, not wanting to mess with Constantine's legacy and fix something they didn't see as broke, refused to allow a change in the calendar (since it would affect the civil calendar as well). By the time the problem was really getting pronounced, and the Eastern Church was using April 3 as the date of the Vernal Equinox for dating purposes (a difference of 13 days), the Christian emperors of Constantinople had been replaced by the Turkish Sultans, who could care less about the date of Pascha.
By that point the church also had been divided into Orthodox East and Roman Catholic west. So, in 1582, Pope Gregory of Rome instituted a revision of the Calendar that is now used in the West, known appropriately as the Gregorian Calendar, the basis for the Roman Catholic date of Easter.
By 1582 Luther, Calvin and King Henry had had their day and many didn't listen to the Pope anymore. So it actually took close to three centuries for the Protestant Churches and their respective countries one by one to accept the Gregorian Calendar.
Meanwhile, some of the Orthodox (Greek, Arabic, American and Romanian in particular) only accepted a partial revision of the Calendar in 1923 that adjusted the fixed feasts such as Christmas but continued to use the Julian Calendar's date for Pascha, so that all Orthodox might continue to celebrate our highest holiday together. Even that change spurred a great deal of controversy as some believed the change to be some kind of capitulation to or compromise with the non-Orthodox, instead of just simply being a matter of adjusting our clocks which had fallen 18,720 minutes behind.
This is where we stand today, and why the Orthodox Church celebrates Pascha frequently much later than Roman Catholics and Protestants celebrate Easter. Perhaps some day the Holy Spirit will guide the Orthodox Churches to adjust the calendar for Pascha. Perhaps not.
In the end, it is not the date of Pascha that saves us but the faith in what it means: the Resurrection of Christ. Christ is risen! Truly He is risen!
XThe Rev. Subu is pastor at Holy Cross Orthodox Church in Hermitage, Pa.