>>854460
Well the Orthodox Church still uses the original method developed by the Church of Alexandria in the 4th and 5th century, which was laid out more explicitly by the computus rules of St. Bede and St. Dionysius Exiguus in the 6th and 7th centuries. The Roman Church and its Protestant descendants just use a slightly modified version of this method that calculates western Easter/Pascha each year (actually there are a few jurisdictions in the Orthodox Church, such as the Orthodox Church of Finland under the Ecumenical Patriarchate, that do celebrate Gregorian Easter/Pascha. Also I think the Syriac Orthodox in the OO communion use the Gregorian date too). I don't know all the subtleties to how its calculated, but I'm looking at a wiki page explaining it all now, seems tedious. You can just keep the simple rules in mind that Pascha takes place on the first Sunday after the first full moon after the equinox (March 21 in both Julian and Gregorian calendars, but with a 13 day difference between each). That's easier to remember than learning all the history behind it and the mathematical rules that goes into it all and it's (generally) reliable. You don't have to know this to be a true theologian though. In fact, all Christians are theologians, in the Orthodox faith theology is not just an academic discipline it is the entire Christian life for everyone. Now, I'm sure the theologians who do like math and science do know about it, and they're the ones who are calculating the date of Pascha for the rest of us faithful, but is it necessary for salvation to know? No. Is the celebration of Pascha itself even necessary for salvation? No. However, the celebration of Pascha does date all the way back to the apostles as the first and original Christian holiday that has an unbroken line of celebration since the apostles, it is part of the Tradition of the Church and should be celebrated. It's the day our Lord resurrected from the dead after all! The start of a new creation!